KR20180007653A - Method and apparatus for transmission and reception of random access preamble in wirelss cellular communication system - Google Patents

Abstract

The present disclosure relates to a communication technique for fusing a 5G communication system with IoT technology to support a higher data rate than a 4G system, and a system thereof. The present disclosure can be used for an intelligent service (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security and safety related service, etc.) based on 5G communication technology and IoT related technology. The present invention discloses a method and apparatus for performing a random access operation on a directional beam based on a frequency band of 6 GHz or more. A method for processing a control signal includes a step of receiving a first control signal transmitted from a base station; a step of processing the received first control signal; and a step of transmitting a second control signal to the base station.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a random access preamble transmission / reception method and apparatus in a wireless cellular communication system,

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for initially connecting a terminal to a network in a next generation mobile communication system.

Efforts are underway to develop an improved 5G or pre-5G communication system to meet the growing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, a 5G communication system or a pre-5G communication system is called a system after a 4G network (Beyond 4G network) communication system or after a LTE system (Post LTE). To achieve a high data rate, 5G communication systems are being considered for implementation in very high frequency (mmWave) bands (e.g., 60 gigahertz (60GHz) bands). In order to mitigate the path loss of the radio wave in the very high frequency band and to increase the propagation distance of the radio wave, in the 5G communication system, beamforming, massive MIMO, full-dimension MIMO (FD-MIMO ), Array antennas, analog beam-forming, and large scale antenna technologies are being discussed. In order to improve the network of the system, the 5G communication system has developed an advanced small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, (D2D), a wireless backhaul, a moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Have been developed. In addition, in the 5G system, the Advanced Coding Modulation (ACM) scheme, Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), the advanced connection technology, Filter Bank Multi Carrier (FBMC) (non-orthogonal multiple access), and SCMA (sparse code multiple access).

On the other hand, the Internet is evolving into an Internet of Things (IoT) network in which information is exchanged between distributed components such as objects in a human-centered connection network where humans generate and consume information. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired / wireless communication, network infrastructure, service interface technology and security technology are required. In recent years, sensor network, machine to machine , M2M), and MTC (Machine Type Communication). In the IoT environment, an intelligent IT (Internet Technology) service can be provided that collects and analyzes data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, and advanced medical service through fusion of existing information technology . ≪ / RTI >

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as a sensor network, a machine to machine (M2M), and a machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antennas It is. The application of the cloud RAN as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

Recently, the New Radio Communication System (NR) should be able to provide various services with different transmission and reception methods, transmission and reception parameters in one system to satisfy various requirements and services of users, It is important to design such that the added services are not constrained by the current system. In NR, a method of transmitting a signal using a wide frequency band existing in a frequency band of 6 GHz or more is considered as a method for increasing the data transmission speed. In this case, a random access operation based on a directional beam is effectively performed in a frequency band of 6 GHz or more A method and apparatus for performing the method are required.

It is an object of the present invention to propose a method and apparatus for performing a directional beam-based random access operation in a frequency band of 6 GHz or more.

It is still another object of the present invention to provide a method and apparatus for providing data transmission and reception for a 5G communication service, and more particularly, to allocate resources for providing future compatibility for the 5G beyond future service, A method of transmitting and receiving data and an apparatus therefor.

It is still another object of the present invention to provide a method for transmitting a time-contiguous reference signal.

According to an aspect of the present invention, there is provided a method of processing a control signal in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; Processing the received first control signal; And transmitting the second control signal generated based on the process to the base station.

According to an embodiment of the present invention, a method of performing a random access procedure appropriately in a communication system supporting Dynamic TDD can provide a UE with increased frequency efficiency by using Dynamic TDD, It is possible to effectively perform the random access procedure. Also, as described above, a beam-based random access procedure can be performed for a terminal that does not know state information of a terminal in a system supporting beam-based data transmission / reception for ensuring coverage as in the frequency band of 6 GHz or more.

According to another embodiment of the present invention, there is provided a method of providing data transmission / reception for a 5G communication service and an apparatus therefor. In particular, resources for providing future compatibility for the 5G beyond future service are allocated, and accordingly, a method of transmitting and receiving data of a terminal and an apparatus therefor are provided.

According to another embodiment of the present invention, a method of transmitting a time-contiguous reference signal is provided, so that channel estimation of a 5G wireless communication system operating in a high frequency band and a low frequency band can be performed effectively .

1A is a diagram illustrating a random access flow between a UE and a base station in conventional LTE in order to describe a random access considered in the present invention in detail.
1B is a diagram showing a structure of transmission resources in the time domain considered in the NR system.
1C is a diagram illustrating a method of setting a random access preamble transmission resource set by the base station in order to transmit a random access preamble in the LTE.
Figure 1d is an illustration of an example of a directional beam (Beam) based transmission considered in an NR system.
1E is a diagram illustrating an example in which a base station performs beam sweeping on a transmission beam of a base station to transmit a synchronization signal and a broadcast channel in a downlink sub-frame.
1F is a diagram illustrating an example of beam sweeping a base station receive beam to receive a random access preamble transmitted from a mobile station in an uplink sub-frame.
FIG. 1G is a flowchart illustrating a method for transmitting a random access preamble by a UE to be considered in an NR system according to an embodiment of the present invention. Referring to FIG.
FIG. 1H is a flowchart illustrating another embodiment of a method for transmitting a random access preamble by a UE considered in an NR system according to an embodiment of the present invention. Referring to FIG.
FIG. 1I is a flowchart illustrating transmission of a random access preamble between a Node B and a UE when the NR system performs signal transmission and reception using a directional beam according to an embodiment of the present invention.
1J and 1K are diagrams illustrating a terminal and a base station apparatus for performing the embodiments of the present invention.
2A shows a basic structure of a time-frequency domain in an LTE system.
2B is a diagram illustrating an example in which 5G services are multiplexed and transmitted in one system.
2C is a diagram showing a first embodiment of a communication system to which the present invention is applied.
2D is a diagram showing a second embodiment of a communication system to which the present invention is applied.
FIG. 2E is a diagram showing situations to be solved in the present invention. FIG.
FIG. 2F is a view showing the embodiment 2-1 of the present invention.
FIG. 2G is a diagram illustrating a procedure of a base station and a terminal according to a second embodiment of the present invention.
2H is a view showing a second embodiment of the present invention.
2I is a diagram illustrating a procedure of a base station and a terminal according to a second embodiment of the present invention.
2J is a diagram illustrating a procedure of a base station and a terminal according to the second and third embodiments of the present invention.
2K is a diagram illustrating a base station apparatus according to the present invention.
FIG. 21 is a diagram illustrating a terminal device according to the present invention.
3A is a diagram illustrating a downlink time-frequency domain transmission structure of a conventional LTE or LTE-A system.
3B is a diagram illustrating an uplink time-frequency domain transmission structure of an LTE or LTE-A system according to the related art.
3C is a diagram illustrating a radio resource of 1 RB which is a minimum unit that can be downlink-scheduled in the LTE or LTE-A system according to the related art.
FIG. 3D is a diagram showing a structure of a time-sequential reference signal and a position in a time-frequency domain according to the embodiment 3-1 of the present invention.
3E is a diagram illustrating a structure of a time-sequential reference signal according to the embodiment 3-1 of the present invention and a specific example of a position in a time-frequency domain.
FIG. 3F is a diagram illustrating an example of a method of allocating an orthogonal transmission layer to a UE through a time-sequential reference signal according to a third exemplary embodiment of the present invention.
FIG. 3G is a diagram illustrating an example of a method of setting a plurality of time-series reference signals according to the embodiment 3-2 of the present invention.
3H is a diagram illustrating an example of a terminal operation using a time-sequential reference signal according to the 3-3 embodiment of the present invention.
3I is a block diagram illustrating an internal structure of a terminal according to embodiments of the present invention.
3J is a block diagram illustrating an internal structure of a base station according to embodiments of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

≪ Embodiment 1 >

The 5th Generation Cellular Communication System (NRC) or the New Radio Communication System (NR) provides various services with different transmission / reception techniques and transmission / reception parameters in one system to satisfy various requirements and services of users. And it is important to design so that there is no restriction that the added service is restricted by the current system in consideration of future compatibility. NR also considers using dynamic TDD to increase frequency efficiency and increase the degree of scheduling freedom over existing LTE (Long Term Evolution). In the existing LTE, a subframe to be used as an uplink and a subframe to be used as a downlink to be used for uplink and downlink in one frequency resource are set in advance, In the NR system, a base station can determine whether to use a specific subframe in an uplink or a downlink according to scheduling based on distribution of terminals in a cell and transmission / reception data requirement. That is, in the dynamic TDD, the switching between the DL subframe and the UL subframe can be dynamically determined in units of subframes. In order to control and manage IDLE STATE terminals in a cell, the BS periodically transmits a broadcast channel including synchronization signals and system information to the terminals, and also transmits an initial access request signal It is necessary to reserve periodic uplink resources to receive the uplink resources. In the present invention, a signal transmitted for the initial connection request by the UE is referred to as a random access preamble, and an operation related thereto will be described in detail. In order for a base station to efficiently control and manage terminals in a cell, a synchronization signal and a broadcast channel must be periodically transmitted, and an uplink resource for transmitting a random access preamble must be set periodically. However, as described above, in the dynamic TDD, the frequency efficiency is increased by determining whether a specific subframe is used as an uplink or a downlink according to the distribution of terminals and transmission / reception data requirements. Therefore, And reception can reduce the efficiency of Dynamic TDD.

Accordingly, the present invention proposes a method and apparatus for performing a random access operation without decreasing the frequency efficiency of the dynamic TDD in the NR supporting the Dynamic TDD.

In addition, NR aims to support increased data transmission rate over existing LTE. As a method for increasing data transmission speed in NR, a method of transmitting a signal using a wide frequency band existing in a frequency band of 6 GHz or more is considered. That is, it is considered to increase the transmission rate by using a millimeter wave (mmWave) band as in the 28 GHz band or the 60 GHz band. Since the frequency band considered for mmWave is relatively large in signal attenuation per distance, directional beam-based transmission using multiple antennas is required for coverage. Directional beam-based transmission has a problem that it is difficult to transmit or receive a signal at a position where no beam is formed. In the case of a connected terminal (CONNECTED STATE), the base station forms an appropriate directional beam according to the state information of the terminal to communicate with the terminal. In the idle state, the base station can not know the state information of the terminal Therefore, a problem that a beam can not be formed may occur. For example, if the reception beam of the base station is not properly formed in the idle terminal that desires initial connection, the base station misses the random access preamble transmitted by the terminal.

 Therefore, the present invention proposes a method and apparatus for performing a random access operation based on a directional beam in a frequency band of 6 GHz or more.

For example, 3GPP's High Speed Packet Access (HSPA), LTE (Long Term Evolution or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced Which provides high-speed and high-quality packet data services such as LTE-A, LTE-Pro, High Rate Packet Data (HRPD) of 3GPP2, Ultra Mobile Broadband (UMB), and IEEE 802.16e Communication system.

In the LTE system, an OFDM (Orthogonal Frequency Division Multiplexing) scheme is used in a downlink (DL) and a Single Carrier Frequency Division Multiple (SC-FDMA) scheme is used in an uplink Access) method. The uplink refers to a radio link through which a UE (User Equipment) or an MS (Mobile Station) transmits data or control signals to a base station (eNode B or base station (BS) The term " wireless link " In the above multiple access scheme, the data or control information of each user is classified and operated so that the time and frequency resources for transmitting data or control information for each user do not overlap each other, that is, orthogonality is established. do.

As a future communication system after LTE, i.e., the NR system is required to provide a data transmission rate that is higher than the data transmission rate supported by existing LTE, LTE-A (Advanced) or LTE-Pro. For example, the NR system should be capable of providing a peak transmission rate of 20 Gbps in the downlink and a maximum transmission rate of 10 Gbps in the uplink from the viewpoint of one base station. In addition, the NR system must provide the maximum transmission rate and at the same time provide the user perceived data rate of the increased terminal.

In order to satisfy the requirements of such NR system, improvement of various transmission / reception technologies including a further improved multi input multiple output (MIMO) transmission technology is demanded. In addition, while the NRT system transmits signals using the maximum transmission bandwidth of 20 MHz in the 2 GHz band used by the current LTE system, the NR system uses a frequency bandwidth wider than 20 MHz in the frequency band of 3 to 6 GHz or more than 6 GHz, Speed can be satisfied. Finally, as a method for increasing the frequency efficiency, Dynamic TDD, which controls transmission and reception times of the uplink and the downlink according to the distribution of terminals and data demand in the cell, can be applied.

Dynamic TDD can switch the uplink and downlink subframes by determining the subframe for the uplink and the downlink appropriately based on the distribution of the terminals in the cell and the amount of data transmission / reception request of the terminal. The TDD of the existing LTE is semi-static TDD, and the patterns of the subframe to be used as the uplink and the subframe to be used as the downlink are set in advance and the uplink and downlink are switched accordingly. Therefore, in the existing LTE TDD, it is difficult to easily control the uplink and downlink time occupation according to the change of the data traffic, so that the frequency efficiency may be reduced. On the other hand, in the case of the above-mentioned Dynamic TDD, since the base station can easily switch between uplink and downlink according to the change of data traffic in the cell, the frequency efficiency can be maximized. However, in order to efficiently control and manage the terminals in the idle state existing in the cell, the synchronization signal and the broadcast channel must be periodically transmitted to the terminals, An access preamble must be received. However, when the dynamic TDD is operated and the synchronous signal, the broadcast channel, and the random access preamble are periodically received, the frequency efficiency of the dynamic TDD may be reduced. That is, when the base station periodically transmits a synchronization signal or a broadcast channel for idle terminals, the subframe transmitting the synchronization signal or the system information should always be fixed in the downlink irrespective of the data traffic situation. Similarly, in order to periodically receive the random access preamble from the idle terminal in which the base station attempts initial connection, the subframe should be periodically fixed in the uplink every predetermined period. When the specific subframe is fixed in the uplink or downlink regardless of the data traffic situation, the frequency efficiency of the base station may be reduced.

Accordingly, the present invention provides a method for performing a random access procedure appropriately in a communication system supporting Dynamic TDD, thereby increasing the frequency efficiency by using Dynamic TDD and performing a random access procedure for an idle terminal efficiently And to provide a method and an apparatus for performing the method.

1A is a diagram illustrating a random access flow between a UE and a base station in conventional LTE in order to describe a random access considered in the present invention in detail.

In FIG. 1A, the base station 1a-001 transmits a synchronization signal and a broadcast channel (1a-003) for synchronization and system information transmission of the terminals 1a-002 in the idle or connected state in the cell. The terminals 1a-003 can synchronize time and frequency with the base station based on the synchronization signal transmitted from the base station, and can detect the cell identity of the base station. The synchronization signal may be composed of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) used in LTE, or may be a combination of additional synchronization signals. The broadcast channel may be used to transmit system information needed to connect to the base station and the cell. As an example of the system information, information necessary for random access of the terminal can be included. The terminals 1a-002 may receive the synchronization signal and the broadcast channel, and may transmit the random access preamble (1a-004) to the base station 1a-001. In the conventional LTE, the UEs 1a-002 can transmit the random access preamble on the basis of the time and frequency transmission resource information and the preamble information of the random access preamble obtained from the broadcast channel. The time and frequency transmission resources of the random access preamble exist at regular intervals, and if the UE determines to transmit the random access preamble, it can transmit a preamble in a random access preamble transmission resource that exists thereafter. The base station 1a-001 attempts to detect the random access preamble transmitted from the terminals in the random access preamble transmission resource set by the base station 1a-001. Generally, the random access preamble can be divided into time, frequency, and code. In LTE, terminals can be distinguished by transmitting different code sequences for each terminal. When the base station 1a-001 detects a random access preamble including a specific code sequence, the base station 1a-001 transmits a response to the random access preamble through the random access response transmission (1a-005). The UEs 1a-002 which have transmitted the random access preamble attempt to receive the random access response for a predetermined time interval after the preamble transmission. The random access response includes information such as resource allocation information, uplink timing control information, and uplink power control information for a UE transmitting a random access preamble to transmit data in the uplink. The UEs 1a-002 receiving the random access response can transmit Layer-2 / Layer-3 message information (1a-006) to the base station according to the uplink resource allocation information included in the random access response. The terminal can use the information obtained from the random access response when transmitting the Layer 2 / Layer 3 message information to the base station (1a-006). Upon receipt of the Layer 2 / Layer 3 message, the base station transmits a collision solving message (1a-007) in response to the Layer 2 / Layer 3 message. The conflict resolution message is transmitted to resolve a conflict that may occur in the random access procedure. That is, when a plurality of terminals transmit the random access preamble using the same code sequence in the random access preamble transmission (1a-004), since a plurality of terminals transmit Layer 2 / Layer 3 messages in the same uplink resource, Lt; / RTI > Therefore, since the collision solving messages (1a-007) are scrambled with unique identifiers included in properly received Layer 2 / Layer 3 messages among Layer 2 / Layer 3 messages transmitted from a plurality of terminals, only the terminal selected by the base station can transmit the collision solving message have.

As shown in FIG. 1A, the synchronization signal and the broadcast channel are periodically transmitted from the base station, and the base station can periodically set resources for random access preamble transmission by the terminal.

1B is a diagram showing a structure of transmission resources in the time domain considered in the NR system.

In FIG. 1B, the structure of the time domain transmission resource is configured in units of a fixed transmission time interval (TTI) (1b-001). The fixed transmission time interval 1b-001 may be composed of a plurality of OFDM symbols. The transmission time interval 1b-001 may include a time interval for downlink transmission and a time interval for uplink transmission. The time interval for downlink transmission includes a time interval 1b-101, 1b-401 and 1b-501 for transmitting a downlink control channel and a time interval 1b-101, 1b- The time interval for transmitting the uplink control channel may include a time interval 1b-404 for transmitting the uplink control channel and a time interval 1b-404 for transmitting the uplink data channel 1b-503 , 1b-602, 1b-702). The transmission time interval 1b-001 may include guard intervals 1b-302, 1b-403, and 1b502 for securing a switching time for switching from the downlink to the uplink. 1B, the NR system includes a transmission resource structure 1b-1 having a downlink control channel, a downlink data channel, an uplink control channel, and an uplink data channel of various lengths within a transmission time interval 1b- 100, 1b-200, 1b-300, 1b-400, 1b-500, 1b-600 and 1b-700. Each channel may be composed of a plurality of OFDM symbols corresponding to time lengths. 1b-100 may be configured with a downlink control channel 1b-101 and a downlink data channel 1b-102. 1b-200 may be configured only as a downlink data channel (1b-201). The transmission resource structure of 1b-300 may be composed of a downlink data channel 1b-301 and a guard interval 1b-302. The transmission resource structure of the mobile station 1b-400 may be composed of a downlink control channel 1b-401, a downlink data channel 1b-402, a guard interval 1b-403 and an uplink control channel 1b-404 . The transmission resource structure of the mobile station 1b-1b-500 may include a downlink control channel 1b-501, a guard interval 1b-502, and an uplink data channel 1b-503. The transmission resource structure of 1b-600 may be composed of a guard interval 1b-601 and an uplink data channel 1b-602. Finally, the transmission resource structure of 1b-700 can be composed only of the uplink data channel 1b-701. Although the present invention is described using the transmission resource structure shown in FIG. 1B, the present invention is not limited to the transmission structure according to 1b, and can be applied to a combination of uplink and downlink channels in various combinations. Of the.

The NR system can be used in combination with the transmission resource structure described in FIG. 1B according to Frequency Division Duplexing (FDD) and TDD. In the case of FDD, 1b-100 and 1b-200 of the transmission resource structure described in FIG. 1B can be used for the downlink frequency. In the uplink frequency, the transmission resource structure 1b-600, 1b-700 and the like can be used. On the other hand, in case of TDD, all transmission resource structures shown in 1b can be used. In the dynamic TDD considered in the present invention, all of the above transmission resource structures can be determined for each subframe according to transmission / reception data transmission traffic, and data can be transmitted or received.

1C is a diagram illustrating a method of setting a random access preamble transmission resource set by the base station in order to transmit a random access preamble in the LTE.

In FIG. 1C, the time-frequency resource (1c-001) may represent an uplink frequency resource in the FDD system and an uplink time resource in the TDD system. The horizontal axis (1c-003) of the time frequency resource means the time axis, and the vertical axis (1c-002) means the frequency axis. The base station can set a transmission resource (1c-004) capable of periodically transmitting a preamble on a time-frequency resource (1c-001) capable of transmitting a signal in an uplink. Accordingly, the preamble transmission resources may appear at specific intervals (1c-005) on the uplink time and frequency resources 1c-001. When a random access preamble transmission resource (1c-004) has a specific period (1c-005) as shown in FIG. 1c, or a subframe including a random access preamble transmission resource is always set to a specific subframe, The frame should be set uplink. In the conventional LTE FDD system, since uplink and downlink are divided into frequencies and uplink frequency resources are always present, there is no problem even if a resource for transmitting a random access preamble is set in a specific subframe. Also, in the TDD system in LTE, since a subframe for downlink transmission and a subframe for uplink transmission are predetermined, if a subframe for transmitting a random access preamble is set among subframes for uplink transmission, Does not occur. However, in the case of operating the dynamic TDD in the NR system, in order to maximize the frequency efficiency, when the base station dynamically switches subframes for uplink and downlink transmission depending on the status of downlink data traffic on the terminals in the cell, There arises a problem that it is difficult to previously set a specific subframe to a subframe for random access preamble transmission as in the prior art. A random access preamble is a signal transmitted from an idle terminal in a cell to a base station for connection to a system. Normally, a base station is difficult to know exactly how many idle terminals exist in a cell. Considering this point, when the specific subframe is set as a subframe for random access preamble transmission while ignoring the data traffic situation, the frequency efficiency may decrease. Therefore, there is a need for a method of setting resources for random access preamble transmission more efficiently.

In the initial connection of the UE in the NR system, consideration of the beam is necessary. As described above, in NR, a method of transmitting a signal using a wide frequency band at a frequency of 6 GHz or more is considered in order to provide an increased data transmission rate. Since the frequency band over 6GHz is relatively large compared with the frequency band below 6GHz, the beam-based signal transmission and reception method using multiple antennas is required to maintain the same coverage.

Figure 1d is an illustration of an example of a directional beam (Beam) based transmission considered in an NR system.

In FIG. 1D, the base station 1d-001 managing one cell can communicate with the terminals 1d-002, 1d-003, 1d-004 in the cell. The area 1d-005 covered by the base station 1d-001 represents the maximum coverage with which the base station 1d-001 can communicate with the terminal when an omni beam is used. As shown in FIG. 1D, when the base station 1d-001 uses an omnidirectional beam instead of a directional beam, the coverage may be reduced according to the path attenuation depending on the distance. For example, the terminals 1d-002 and 1d-003 can communicate with the base station 1d-001 through the omnidirectional beam in FIG. 1d. However, in the case of the terminal 1d-004, the path attenuation is relatively large, Communication with an omnidirectional beam is impossible. For such a terminal, the base station can improve the coverage using the directional beams 1d-006. However, although the directional beam can improve the coverage, since the beam width is narrower than that of the omnidirectional beam, communication is difficult when the direction of the beam does not exactly coincide with the terminal and the base station. For example, since the beam 1d-006 formed toward the terminal 1d-004 in FIG. 1d does not face the terminals 1d-002 and 1d-003, the terminals 1d-002 and 1d-003 use the beams 1d- 001) is difficult to communicate with.

In case of a terminal connected to a base station, the beam-based signal transmission / reception transmits channel state information measured using a reference signal for measuring channel state information transmitted from the base station to the base station However, in the case of an idle terminal that is not connected to the base station in the cell, it is difficult for the terminal to transmit the channel state information to the base station. Therefore, There is a problem that the beam can not be formed. In the above example, there may occur a problem that the coverage of the synchronization signal, the broadcast channel, and the random access preamble transmitted for initial connection by the terminal, which are signals necessary for synchronization and system initial connection, may be reduced.

In order to solve such a problem, in the related art, a base station transmits a synchronous signal, a broadcast channel, and the like on a beam-based basis. In order to solve the problem of inconsistency of a beam direction, Beam sweeping techniques are being considered. Also, in order to receive a random access preamble transmitted by a mobile station, a base station exchanges a beam for each specific preamble transmission resource time, and receives the random access preamble.

1E is a diagram illustrating an example in which a base station performs beam sweeping on a transmission beam of a base station to transmit a synchronization signal and a broadcast channel in a downlink sub-frame.

In FIG. 1E, a plurality of downlink subframes 1e-001 to 1e-005 may be transmitted using one beam 1e-006 to 1e-010. The beams 1e-006 to 1e-010 used for transmission are directional beams formed in a specific direction. As described above, in order to solve the problem that a directional beam can not receive a signal in a direction in which the beam does not fit, the cell covers all directions during the plurality of downlink subframes 1e-001 to 1e-005 The signals can be transmitted using beams formed in different directions for each subframe. 1E shows an example in which a beam is transmitted in a clockwise direction for each subframe in order to transmit a sync signal and a broadcast channel in all directions during consecutive downlink subframes.

1F is a diagram illustrating an example of beam sweeping a base station receive beam to receive a random access preamble transmitted from a mobile station in an uplink sub-frame.

In Fig. 1F, a plurality of uplink subframes 1f-001 to 1f-005 may be received using one beam 1f-006 to 1f-010. At this time, the beams 1f-006 to 1f-010 used for uplink reception are directional beams formed toward a specific direction. As described above, the directional beam has a problem that the base station can not receive the signal even if a terminal in a direction in which the beam does not match transmits a signal. To solve this problem, a plurality of uplink subframes 1f-001 to 1f- 005), the signal can be received using beams formed in different directions for each subframe so that the cell covers all directions. FIG. 1F shows an example in which a beam is received in a clockwise direction for each subframe in order to receive a random access preamble in all directions during consecutive uplink subframes.

A method of transmitting a synchronization signal and broadcast information and receiving a random access preamble to an idle terminal in which all directions exist in a base station using beam sweeping as described above has been described. However, as described above, when a reception beam is formed in a specific direction for receiving a random access preamble in a specific subframe, frequency efficiency may decrease. Considering the complexity and implementation of the terminal in a frequency band of 6 GHz or more, only one beam can be formed in a specific direction in one time. That is, since a base station transmits or receives signals with two beams to terminals located at different positions requires high complexity, one subframe forms a transmission beam or a reception beam directed in one direction. In this case, when a base station forms a reception beam in a specific direction to receive a random access preamble, when there is no user in that direction, it is difficult to schedule data for a terminal other than a resource for receiving a random access preamble A problem occurs. In such a case, there is a problem that frequency efficiency is reduced due to waste of uplink frequency resources.

Therefore, according to the present invention, in order to receive a random access preamble transmitted from a mobile station in an idle state in the dynamic TDD, it is possible to minimize a frequency efficiency decrease caused by fixing a specific subframe as an uplink subframe at all times, We propose a method of setting resources.

Also, in the present invention, in a transmission / reception system based on a directional beam, when base station reception beam sweeping is performed to receive a random access preamble transmitted by a mobile station in order to support initial access of an idle state terminal, We propose a method for setting up resources for efficient random access preamble transmission while minimizing the reduction of frequency efficiency that may occur when fixed with a beam.

The embodiment of the present invention minimizes a reduction in frequency efficiency caused by fixing a specific subframe to an uplink subframe in order to receive a random access preamble transmitted from a mobile station in an idle state in Dynamic TDD, We propose a method to set resources for

Also, in the present invention, in a transmission / reception system based on a directional beam, when base station reception beam sweeping is performed to receive a random access preamble transmitted by a mobile station in order to support initial access of an idle state terminal, We propose a method to set up resources for efficient random access preamble transmission while minimizing the reduction of frequency efficiency that may occur when fixed with a beam.

FIG. 1G is a flowchart illustrating a method for transmitting a random access preamble by a UE to be considered in an NR system according to an embodiment of the present invention. Referring to FIG.

In FIG. 1G, the base station 1g-001 may periodically transmit the synchronization signal 1g-003 for the terminal 1g-002 existing in the cell. The base station 1g-001 can transmit the synchronization signal 1g-003 by using a forward beam or using a directional beam. In general, it is preferable to transmit the synchronization signal (1g-003) using the omni-directional beam in the frequency band of 6 GHz or less, and to transmit the synchronization signal (1g-003) using the directional beam in the frequency band of 6 GHz or more In the present invention, the present embodiment can be applied regardless of the beam type used for a specific frequency band. In the case of the synchronous signal, it is assumed that the synchronous signal (1g-003) is transmitted in the fixed downlink subframe in consideration of the complexity of the terminal for synchronous signal detection and base station operation. It is also assumed that a synchronous signal (1g-003) is transmitted using a directional beam formed in a specific direction in a specific downlink subframe even when a directional beam is used to transmit the synchronous signal (1g-003). In the case of TDD, since the downlink data traffic is generally larger than the uplink data traffic, it can be assumed that the frequency efficiency reduction is small even in the case of transmitting the downlink synchronous signal with a beam fixed to the fixed subframe . The terminal 1g-002 performs time and frequency synchronization on the synchronization signal transmitted from the base station 1g-001 and acquires the cell number through the cell search 1g-004.

The base station 1g-001 periodically transmits the broadcast channel 1g-005 for the terminal 1g-002 in the cell in the second step. The base station 1g-001 can transmit a broadcast channel 1g-005 using a forward beam or a directional beam. In general, it is preferable to transmit the broadcast channel 1g-005 using the omnidirectional beam in a frequency band of 6 GHz or less, similar to the sync signal 1g-003. In a frequency band of 6 GHz or more, It is preferable to transmit the broadcast channel 1g-005. However, in the present invention, the present embodiment can be applied regardless of the beam type used for a specific frequency band. It is assumed that the broadcast channel 1g-005 is also transmitted with the synchronization signal 1g-003, so it is assumed that the broadcast channel 1g-005 is transmitted in the fixed downlink subframe. Also, in the case of transmitting a broadcast channel 1g-005 using a directional beam, it is assumed that a broadcast channel 1g-005 is transmitted using a directional beam formed in a specific direction in a specific downlink subframe. The terminal 1g-002 can receive (1g-006) the system information related to the NR system by receiving the broadcast channel 1g-005 transmitted by the base station 1g-001. The system information acquired by the terminal 1g-002 includes information related to the terminal performing random access. At this time, the random access-related system information may include the following information.

- The random access preamble sequence information

- Random access preamble format

- Random access power control information

- Time and frequency resource information for random access preamble transmission

Then, the terminal 1g-002 that wants to initially access the system transmits a random access preamble in which subframe based on the time and frequency resource information for random access preamble transmission among the random access related information acquired from the broadcast information . Thereafter, the terminal 1g-002 receives the downlink control channel 1g-008 in the subframe 1g-007 set to transmit the random access preamble transmission resource from the base station 1g-001. In this case, if the random access preamble transmission indicator is not included in the received downlink control channel 1g-008, the terminal 1g-002 determines that the corresponding subframe is a subframe for random access preamble transmission The random access preamble is not transmitted in the corresponding subframe. Then, the terminal 1g-002 receives the downlink control channel 1g-010 in another subframe 1g-009 set to transmit the next random access preamble transmission resource resource. If the random access preamble transmission indicator is included in the received downlink control channel 1g-010 and the indicator indicates to transmit the preamble, the terminal 1g-002 transmits a random access preamble in the corresponding subframe 1g -011). At this time, the frequency resource through which the UE transmits the random access preamble can be transmitted through the preset frequency resource through the system information.

The embodiment illustrated in FIG. 1G may be embodied in the following detailed method.

In the method 1 according to the present embodiment, as shown in FIG. 1G, a base station for transmitting a random access preamble includes a transmission resource structure 1b-400, 1b- 500), an indicator indicating that the UE can transmit the random access preamble in the corresponding DL control channel can be transmitted. The UE attempts to detect an indicator indicating that a random access preamble can be transmitted in a predetermined subframe for random access preamble transmission. When the UE detects a corresponding indicator in the downlink control channel and instructs the indicator to transmit a preamble, the UE allocates resources (1b-404) for the uplink control channel included in the corresponding subframe, resources It is possible to transmit the random access preamble according to the format set by the mobile station 1b-503. If the time interval is short for the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel to transmit the random access preamble in the preset format, the UE transmits a random access preamble Do not transmit. Also, when the uplink is longer than one transmission time interval (1b-001) according to the combination of the transmission resource structure of FIG. 1B, a larger random access preamble format transmission is also possible. If the corresponding indicator is not detected in the downlink control channel, or if the detected indicator indicates not to transmit the preamble, the terminal does not transmit the preamble in the corresponding subframe. For the method 1, the downlink control channel may include a random access preamble transmission indicator, which may be a downlink control channel having a separate structure. In the current LTE, a common search space And may be transmitted in the same format as the downlink control information.

In the method 2 according to the present embodiment, as shown in FIG. 1G, a base station for transmitting a random access preamble includes a transmission resource structure 1b-400, 1b- 500), an indicator indicating that the UE can transmit a random access preamble in the corresponding downlink control channel can be transmitted. At this time, the base station may additionally add an additional transmission timing field indicating to transmit the random access preamble after any subframe from the current subframe. The UE attempts to detect an indicator and a transmission timing field indicating that a random access preamble can be transmitted in a predetermined subframe for random access preamble transmission. If the random access preamble transmission indicator indicates the preamble transmission, the terminal may wait for the number of subframes indicated by the transmission timing field from the end of the subframe before transmitting the random access preamble. For example, if two subframes are indicated in the transmission timing field, the UE may transmit a random access preamble after two subframes from the end of the subframe that received the corresponding downlink control channel. If the time interval is short for the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel to transmit the random access preamble in the preset format, the UE transmits a random access preamble Do not transmit. Also, when the uplink is longer than one transmission time interval (1b-001) according to the combination of the transmission resource structure of FIG. 1B, a larger random access preamble format transmission is also possible. If the corresponding indicator is not detected in the downlink control channel, or if the detected indicator indicates not to transmit the preamble, the terminal does not transmit the preamble in the corresponding subframe. For the above method 2, the downlink control channel may include an indicator for instructing transmission of a random access preamble and a transmission timing field for indicating a subframe capable of transmitting a random access preamble, Link control channel, or may be transmitted in a format such as downlink control information through the common search space in the current LTE.

In the method 3 according to the present embodiment, as shown in FIG. 1G, a base station for transmitting a random access preamble includes a transmission resource structure 1b-400, 1b- 500), the idle terminal in the DL control channel can transmit a transmission resource structure indicator indicating the transmission resource structure of the current subframe. The UE attempts to detect a transmission resource structure indicator indicating a transmission resource structure of the current subframe in a predetermined subframe for random access preamble transmission. The transmission resource structure indicator is an indicator for indicating which transmission resource structure the current subframe uses among the various transmission resource structures shown in FIG. 1B. When the UE detects a corresponding indicator in the downlink control channel and the corresponding subframe includes the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel through the corresponding indicator , The UE can transmit the random access preamble according to the format set in the resource 1b-404 for the uplink control channel included in the corresponding subframe or the resource 1b-503 for the uplink data channel. If the time interval is short for the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel to transmit the random access preamble in the preset format, the UE transmits a random access preamble Do not transmit. If the corresponding indicator is not detected in the downlink control channel or if the detected indicator indicates that the corresponding subframe is a resource 1b-404 for the uplink control channel or a resource 1b-404 for the uplink data channel, 503), the UE does not transmit a preamble in the corresponding subframe. For the method 3, the downlink control channel may include a transmission resource structure indicator of the corresponding subframe, which may be a downlink control channel having a separate structure. In the current LTE, a common search space ) In the same format as the downlink control information.

In the method 4 according to the present embodiment, as shown in FIG. 1G, a base station for transmitting a random access preamble includes a transmission resource structure 1b-600 or 1b-700 in which a predetermined subframe for a random access preamble transmission includes only an uplink channel, , The UE can transmit the random access preamble in the corresponding subframe regardless of the downlink control channel reception. Here, when the uplink is longer than one transmission time interval (1b-001) according to the combination of the transmission resource structure of FIG. 1B, a larger random access preamble format transmission is also possible.

The methods 1, 2, 3, and 4 according to the present embodiment operate based on the system information for random access being transmitted in advance through a broadcast channel. That is, the time and frequency resources for random access preamble transmission are preset in advance in the system information for random access, and the indicator included in the downlink control channel or the transmission resource structure of the corresponding subframe in the corresponding subframe And a method for transmitting a random access preamble according to the present invention.

In the following embodiments, a method of operating a terminal without setting time and frequency resources for random access preamble transmission to system information for random access is proposed.

FIG. 1H is a flowchart illustrating another embodiment of a method for transmitting a random access preamble by a UE considered in an NR system according to an embodiment of the present invention. Referring to FIG.

In FIG. 1H, the base station 1h-001 may periodically transmit the synchronization signal 1h-003 for the terminals 1h-002 existing in the cell. The base station 1h-001 can transmit the synchronization signal 1h-003 using the omni-directional beam or the directional beam. In general, it is preferable to transmit a synchronous signal (1h-003) using a forward beam in a frequency band of 6 GHz or less, and transmit a synchronous signal (1h-003) using a directional beam in a frequency band of 6 GHz or more In the present invention, the present embodiment can be applied regardless of the beam type used for a specific frequency band. In the case of the synchronous signal, it is assumed that the synchronous signal (1h-003) is transmitted in the fixed downlink subframe in consideration of the complexity of the terminal for synchronous signal detection and the base station operation. It is also assumed that a synchronous signal (1h-003) is transmitted using a directional beam formed in a specific direction in a specific downlink subframe even when a directional beam is used to transmit the synchronous signal (1h-003). In the case of TDD, since the downlink data traffic is generally larger than the uplink data traffic, it can be assumed that the frequency efficiency reduction is small even in the case of transmitting the downlink synchronous signal with a beam fixed to the fixed subframe . The terminal 1h-002 performs time and frequency synchronization on the synchronization signal transmitted from the base station 1h-001 and obtains the cell number through the cell search (1h-004).

The base station 1h-001 periodically transmits the broadcast channel 1h-005 for the terminal 1h-002 in the cell at the second stage. The base station 1h-001 can transmit a broadcast channel 1h-005 using a forward beam or a directional beam. In general, it is preferable to transmit the broadcast channel 1h-005 using the omnidirectional beam in the frequency band of 6 GHz or less, similar to the synchronous signal 1h-003 described above. In the frequency band of 6 GHz or more, It is preferable to transmit the broadcast channel 1h-005. However, in the present invention, the present embodiment can be applied regardless of the beam type used for a specific frequency band. It is assumed that the broadcast channel 1h-005 is also transmitted together with the synchronization signal 1h-003, so it is assumed that the broadcast channel 1h-005 is transmitted in the fixed downlink subframe. Also, in the case of transmitting a broadcast channel (1h-005) using a directional beam, it is assumed that a broadcast channel (1h-005) is transmitted using a directional beam formed in a specific direction in a specific downlink subframe. The terminal 1h-002 can receive (1h-006) the system information related to the NR system by receiving the broadcast channel 1h-005 transmitted by the base station 1h-001. The system information acquired by the terminal 1h-002 includes information related to the terminal performing random access. At this time, the random access-related system information may include the following information.

- The random access preamble sequence information

- Random access preamble format

- Random access power control information

Unlike the flow described in FIG. 1G, information on time resources for preamble transmission is not set in system information related to random access. That is, it is not set to which subframe the random access preamble should be transmitted. Then, the terminal 1h-002 that desires to initially access the system receives the downlink control channel 1h-007. At this time, if the random access preamble transmission indicator is not included in the received downlink control channel 1h-007, the terminal 1h-002 does not transmit the random access preamble in the corresponding subframe. Thereafter, the terminal 1h-002 receives the downlink control channel 1g-008 in another subframe. If the random access preamble transmission indicator is included in the received downlink control channel 1h-008 and the indicator instructs to transmit a preamble, the terminal 1h-002 transmits a random access preamble in the corresponding subframe 1h -009). At this time, the frequency resource through which the UE transmits the random access preamble can be transmitted through the preset frequency resource through the system information. If the frequency resource for transmitting the random access preamble is not set in advance in the system information, the base station can transmit the area of the frequency resource for transmitting the random access preamble together with the random access preamble transmission indicator to the downlink control channel. When a random access preamble transmission indicator is included in the received downlink control channel (1h-008) and the indicator instructs to transmit a preamble, the UE receives the frequency resource information and generates a random access preamble Lt; / RTI >

The embodiment illustrated in FIG. 1h may be embodied in the following detailed method.

In the method 5 according to the present embodiment, as shown in FIG. 1H, the BS may transmit an indicator indicating that the UE can transmit a random access preamble on all downlink control channels for the random access preamble transmission operation. When the UE detects a corresponding indicator in the downlink control channel and instructs the indicator to transmit a preamble, the UE allocates resources (1b-404) for the uplink control channel included in the corresponding subframe, resources It is possible to transmit the random access preamble according to the format set by the mobile station 1b-503. At this time, if a frequency resource for transmitting the random access preamble is set on the downlink control channel, the UE transmits a random access preamble accordingly. If the time interval is short for the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel to transmit the random access preamble in the preset format, the UE transmits a random access preamble Do not transmit. Also, when the uplink is longer than one transmission time interval (1b-001) according to the combination of the transmission resource structure of FIG. 1B, a larger random access preamble format transmission is also possible. If the corresponding indicator is not detected in the downlink control channel, or if the detected indicator indicates not to transmit the preamble, the terminal does not transmit the preamble in the corresponding subframe. For the method 5, the downlink control channel may include a random access preamble transmission indicator, which may be a downlink control channel having a separate structure. In the present LTE, a common search space And may be transmitted in the same format as the downlink control information.

In the method 6 according to the present embodiment, as shown in FIG. 1H, the BS may transmit an indicator indicating that the UE can transmit the random access preamble on all downlink control channels for the random access preamble transmission operation. At this time, the base station may additionally add an additional transmission timing field indicating to transmit the random access preamble after any subframe from the current subframe. If the random access preamble transmission indicator indicates the preamble transmission, the terminal may wait for the number of subframes indicated by the transmission timing field from the end of the subframe and transmit the random access preamble. For example, if two subframes are indicated in the transmission timing field, the UE may transmit a random access preamble after two subframes from the end of the subframe that received the corresponding downlink control channel. At this time, if a frequency resource for transmitting the random access preamble is set on the downlink control channel, the UE transmits a random access preamble accordingly. If the time interval is short for the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel to transmit the random access preamble in the preset format, the UE transmits a random access preamble Do not transmit. Also, when the uplink is longer than one transmission time interval (1b-001) according to the combination of the transmission resource structure of FIG. 1B, a larger random access preamble format transmission is also possible. If the corresponding indicator is not detected in the downlink control channel, or if the detected indicator indicates not to transmit the preamble, the terminal does not transmit the preamble in the corresponding subframe. For the method 6, the downlink control channel may include an indicator for instructing transmission of a random access preamble and a transmission timing field for indicating a subframe capable of transmitting a random access preamble, Link control channel, or may be transmitted in a format such as downlink control information through the common search space in the current LTE.

In the method 7 according to the present embodiment, as shown in FIG. 1H, the BS may transmit a transmission resource structure indicator indicating that the idle terminal knows the transmission resource structure of the current subframe in all downlink control channels for the random access preamble transmission operation. The transmission resource structure indicator is an indicator for indicating which transmission resource structure the current subframe uses among the various transmission resource structures shown in FIG. 1B. The UE detects a corresponding indicator in the downlink control channel and determines that the corresponding subframe includes the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel , The UE can transmit the random access preamble according to the resource (1b-404) for the uplink control channel included in the corresponding subframe or the format set by the resource (1b-503) for the uplink data channel. At this time, if a frequency resource for transmitting the random access preamble is set on the downlink control channel, the UE transmits a random access preamble accordingly. If the time interval is short for the resource 1b-404 for the uplink control channel or the resource 1b-503 for the uplink data channel to transmit the random access preamble in the preset format, the UE transmits a random access preamble Do not transmit. If the corresponding indicator is not detected in the downlink control channel or if the detected subframe includes the resource 1b-404 for the uplink control channel and the resource 1b-404 for the uplink data channel, 503), the UE does not transmit a preamble in the corresponding subframe. For the method 7, the downlink control channel may include a transmission resource structure indicator of the corresponding subframe, which may be a downlink control channel having a separate structure. In the current LTE, a common search space ) In the same format as the downlink control information. It may be considered that the base station performs a transmission / reception operation with the terminal using the directional beam with respect to the methods 1 to 7 described above according to the embodiment of the present invention. In this case, in the present invention, the base station can additionally transmit directional beam information for receiving uplink in the corresponding subframe to the downlink control channel. In the present invention, this is referred to as uplink receiving beam information, and the corresponding beam information may be indicated by a specific number matching the beam direction. The UL receiving beam information is information for instructing the BS to form a beam in a certain direction in receiving an arbitrary subframe. The beam formed in each direction has a unique index and the UL receiving beam information can refer to the index. In the course of performing a cell search using a downlink synchronization signal, the UE can know which beam is suitable for transmission and reception with the base station. That is, the BS knows uplink reception beam information suitable for receiving a signal transmitted by the BS. Accordingly, the UE determines that the corresponding subframe is a subframe in which the random access preamble can be transmitted according to the methods 1 to 7, and simultaneously the base station uplink reception beam formed by the base station for receiving the uplink reception beam in the corresponding subframe, If it is matched with the predicted link reception beam, the random access preamble can be transmitted in the corresponding subframe.

FIG. 1I is a flowchart illustrating transmission of a random access preamble between a Node B and a UE when the NR system performs signal transmission and reception using a directional beam according to an embodiment of the present invention.

In FIG. 1I, the base station 1i-001 may periodically transmit a plurality of synchronization signals 1i-003 and i-004 for a terminal 1i-002 existing in a cell. The plurality of synchronization signals (1i-003, i-004) may be transmitted using different directional beams. For example, the synchronization signal 1i-003 is transmitted in a directional beam having a direction designated by the first beam, and the synchronization signal 1i-004 is transmitted in a directional beam transmitted in a direction set in the nth beam. The terminal can complete the cell search (1i-005) using the sync signal transmitted to itself from among the plurality of sync signals (1i-003, i-004). When the terminal 1i-002 completes the cell search, the terminal can detect information on the transmission beam and the reception beam of a suitable base station in performing communication with the base station. That is, the terminal can estimate the downlink transmission beam information and the uplink reception beam information suitable for the base station communication by the terminal. The terminal acquires system information (1g-006) by acquiring the broadcast channel (1g-005) transmitted by the base station. As described above, the random access-related information among the system information may include the following information.

- The random access preamble sequence information

- Random access preamble format

- Random access power control information

- Time and frequency resource information for random access preamble transmission

Thereafter, the terminal 1g-002 receives a random access preamble transmission indicator, a transmission resource structure of the corresponding subframe, or a random access preamble transmission indicator in accordance with the methods 1 to 7 in receiving the downlink control channel 1g-008 from the base station 1g- And receive the uplink reception beam information of the base station in addition to the transmission timing field. At this time, the uplink reception beam information of the base station received on the downlink control channel is information on the directional beam that the base station sets to receive the corresponding subframe in the uplink. The UE can transmit the random access preamble in the corresponding subframe if the information of the uplink BS reception beam set to the DL control channel and the information of the reception beam of the base station estimated to be the synchronization channel by the UE coincide with each other. If the UE does not coincide with the uplink beamforming information of the base station estimated by the uplink beam information received in the downlink control channel in the corresponding subframe, the UE does not transmit the random access preamble in the corresponding subframe. When the base station performs a transmission / reception operation using a directional beam for the above operation, in order to transmit a random access preamble of the UE, the Node B must transmit information on a beam to be used when receiving the uplink to the downlink control channel. The UE must be able to determine whether the uplink received beam information obtained on the downlink control channel and the information on the base station uplink receive beam that it knows through the cell search match.

The NR system considered in the present invention sets a random access resource for the UE and the UE transmits the random access preamble accordingly through the methods 1 to 7 described above. Further, a plurality of methods 1 to 7 may be combined, and details of how to make an invention in combination are not described in the present invention, but do not depart from the scope of the invention.

Although the present invention has been described with respect to the embodiments and methods of the present invention mainly focusing on Dynamic TDD, the present invention can be similarly applied to TDD and FDD.

1J and 1K are diagrams illustrating a terminal and a base station apparatus for performing the embodiments of the present invention. According to the random access preamble transmission / reception method of the NR system proposed in the above embodiment, the UE and the base station apparatus must operate.

1J is a block diagram showing an internal structure of a terminal device according to an embodiment of the present invention. 1J, the terminal apparatus of the present invention includes an RF unit 1j-01, a random access preamble generator 1j-02, a synchronization and cell searcher 1j-03, a broadcast channel receiver 1j- , A controller (1j-05), and an antenna (1j-06). The RF unit 1j-01 converts the baseband signal into a transition band signal and transmits the baseband signal to the antenna or converts the signal received from the antenna to baseband in order to transmit the signal through the antenna, The synchronization and cell searcher 1j-03 performs frequency and time synchronization and cell search using the synchronization signal transmitted from the base station. The broadcast channel receiver 1j-04 receives the broadcast channel transmitted by the base station and acquires system information necessary for random access and the like. The random access preamble generator 1j-02 generates and transmits a random access preamble when the terminal needs to access the cell. The controller 1j-05 includes an RF section 1j-01, a random access preamble generator 1j-02, a synchronous and cell searcher 1j-03, a broadcast channel receiver 1j-04, a controller 1j- And the antennas 1j-06 so that the terminal can perform synchronization, cell search, system information acquisition, and random access preamble transmission.

1K is a block diagram illustrating an internal structure of a base station apparatus according to an embodiment of the present invention. 1K, the base station apparatus includes an RF unit 1k-01, a synchronous signal transmitting unit 1k-02, a broadcast channel transmitting unit 1k-03, a random access preamble detector 1k-04 , A control unit 1k-05, and an antenna 1k-06. The RF unit 1k-01 converts the baseband signal into a transition band signal to transmit the signal through the antenna, and transmits the baseband signal to the antenna. The RF unit 1k-01 converts the signal received from the antenna into a baseband signal and outputs the signal to the random access preamble detector 1k- The synchronization signal transmitting unit 1k-02 transmits a synchronization signal so that the terminal can perform frequency and time synchronization using the synchronization signal. The broadcast channel transmission unit 1k-04 transmits a broadcast channel so that the terminal can acquire system information. The random access preamble detector 1k-04 performs an operation of detecting a random access preamble transmitted by the UE. The controller 1k-05 includes an RF unit 1k-01, a synchronous signal transmitting unit 1k-02, a broadcast channel transmitting unit 1j-03, a random access preamble detector 1k- ) So that the terminal can perform synchronization, cell search, system information acquisition, and random access preamble transmission.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of the present invention in order to facilitate the understanding of the present invention and are not intended to limit the scope of the present invention. That is, it will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible. Further, each of the above embodiments can be combined with each other as needed.

≪ Embodiment 2 >

The present invention relates to a wireless communication system, and more particularly, to a wireless communication system in which different wireless communication systems coexist in one carrier frequency or a plurality of carrier frequencies and can transmit / receive data in at least one communication system among different communication systems. And a method and an apparatus for transmitting / receiving data to / from each communication system.

Generally, a mobile communication system has been developed to provide voice service while ensuring the user's activity. However, the mobile communication system is gradually expanding not only to voice but also to data service, and now it has developed to the extent of providing high-speed data service. However, in a mobile communication system in which a service is currently provided, a lack of resources and users demand higher speed services, and therefore, a more advanced mobile communication system is required.

As a system under development in the next generation mobile communication system in response to this demand, standard works for LTE (Long Term Evolution) are underway in the 3rd Generation Partnership Project (3GPP). LTE is a technology that implements high-speed packet-based communications with transmission rates of up to 100 Mbps. Various methods are discussed for this purpose. For example, there is a method of reducing the number of nodes located on a communication path by simplifying the structure of a network, and a method of approaching wireless protocols to a wireless channel as much as possible.

The LTE system adopts a Hybrid Automatic Repeat reQuest (HARQ) scheme in which a physical layer resends data when a decoding failure occurs in an initial transmission. In the HARQ scheme, when a receiver fails to correctly decode data, a receiver transmits information (NACK: Negative Acknowledgment) indicating decoding failure to the transmitter so that the transmitter can retransmit the corresponding data in the physical layer. The receiver combines the data retransmitted by the transmitter with data that has not been decoded previously, thereby improving data reception performance. In addition, when the receiver correctly decodes the data, an acknowledgment (ACK) indicating the decoding success is transmitted to the transmitter so that the transmitter can transmit new data.

FIG. 2A is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource region in which data or a control channel is transmitted in a downlink in an LTE system.

In FIG. 2A, the horizontal axis represents time domain and the vertical axis represents frequency domain. The minimum transmission unit in the time domain is an OFDM symbol. N _symb (2a-02) OFDM symbols constitute one slot 2a-06, and two slots are gathered to form one subframe 2a-05. . The length of the slot is 0.5 ms and the length of the subframe is 1.0 ms. The radio frame 2a-14 is a time-domain unit composed of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is composed of a total of N _BW (2a-04) subcarriers.

In a time-frequency domain, a basic unit of a resource can be represented by an OFDM symbol index and a subcarrier index as a resource element (2a-12). A resource block (RB or Physical Resource Block (PRB) 2a-08) includes N _symb (2a-02) consecutive OFDM symbols in the time domain and N _RB (2a-10) . Therefore, one RB 2a-08 is composed of N _symb x N _RB REs 2a-12. In general, the minimum transmission unit of data is the RB unit. In the LTE system, N _symb = 7, N _RB = 12, and N _BW and N _RB are generally proportional to the bandwidth of the system transmission band. The data rate increases in proportion to the number of RBs scheduled to the UE. The LTE system defines and operates six transmission bandwidths. In the case of an FDD system in which the downlink and the uplink are classified by frequency, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Table 1 below shows the correspondence relationship between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system with a 10 MHz channel bandwidth has a transmission bandwidth of 50 RBs.

[Table 1]

In the case of downlink control information, it is transmitted within the first N OFDM symbols in the subframe. In general, N = {1, 2, 3}. Therefore, the N value varies with each subframe according to the amount of control information to be transmitted in the current subframe. The control information includes a control channel transmission interval indicator indicating how many OFDM symbols control information is transmitted, scheduling information for downlink data or uplink data, and an HARQ ACK / NACK signal.

In the LTE system, scheduling information for downlink data or uplink data is transmitted from a base station to a mobile station through downlink control information (DCI). An uplink (UL) refers to a radio link through which a terminal transmits data or control signals to a base station, and a downlink (DL) refers to a radio link through which a base station transmits data or control signals to a terminal. The DCI defines various formats to determine whether it is scheduling information (uplink grant) for uplink data or scheduling information (DL (downlink) grant) for downlink data, a compact DCI Whether to apply spatial multiplexing using multiple antennas, whether DCI is used for power control, and the like. For example, DCI format 1, which is scheduling control information (DL grant) for downlink data, is configured to include at least the following control information.

- Resource allocation type 0/1 flag: Notifies whether the resource allocation method is Type 0 or Type 1. Type 0 allocates resources by resource block group (RBG) by applying bitmap method. In the LTE system, the basic unit of scheduling is an RB (resource block) represented by a time and frequency domain resource, and the RBG is composed of a plurality of RBs and serves as a basic unit of scheduling in the type 0 scheme. Type 1 allows a specific RB to be allocated within the RBG.

- Resource block assignment: Notifies the RB allocated to data transmission. The resources to be represented are determined according to the system bandwidth and the resource allocation method.

- Modulation and coding scheme (MCS): Notifies the modulation scheme used for data transmission and the size of the transport block, which is the data to be transmitted.

- HARQ process number: Notifies the HARQ process number.

- New data indicator: Notifies HARQ initial transmission or retransmission.

- Redundancy version: Notifies the redundancy version of HARQ.

- (Transmit Power Control) command for PUCCH (Physical Uplink Control CHannel): Notifies a transmission power control command for the uplink control channel PUCCH.

The DCI is transmitted through a Physical Downlink Control Channel (PDCCH) or an Enhanced PDCCH (EPDCCH) through a channel coding and modulation process.

Generally, the DCI is independently channel-coded for each UE, and then is composed of independent PDCCHs and transmitted. In the time domain, the PDCCH is mapped and transmitted during the control channel transmission period. The frequency domain mapping position of the PDCCH is determined by the identifier (ID) of each terminal and spread over the entire system transmission band.

The downlink data is transmitted through a Physical Downlink Shared Channel (PDSCH), which is a physical channel for downlink data transmission. The PDSCH is transmitted after the control channel transmission interval. The scheduling information such as the specific mapping position in the frequency domain, the modulation scheme, and the like is notified by the DCI transmitted through the PDCCH.

The base station notifies the UE of a modulation scheme applied to a PDSCH to be transmitted and a transport block size (TBS) to be transmitted through an MCS having 5 bits among the control information constituting the DCI. The TBS corresponds to a size before channel coding for error correction is applied to data (transport block, TB) to be transmitted by the base station.

The modulation schemes supported by the LTE system are QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), and 64QAM, and the respective modulation orders (Q _m ) correspond to 2, 4, and 6, respectively. That is, 2 bits per symbol for QPSK modulation, 4 bits per symbol for 16QAM modulation, and 6 bits per symbol for 64QAM modulation.

In 3GPP LTE Rel-10, bandwidth expansion technology was adopted to support higher data transmission compared with LTE Rel-8. The above technique called Bandwidth extension or Carrier Aggregation (CA) can increase the amount of data transmission by an extended band compared to the LTE Rel-8 terminal that transmits data in one band by extending the band . Each of the above-mentioned bands is referred to as a constituent carrier (CC), and the LTE Rel-8 terminal is defined to have one constituent carrier wave for each of the downward and upward directions. Also, the downlink carrier wave and the uplink carrier wave that are connected to the SIB-2 are bundled and called a cell. The SIB-2 connection relationship between the downlink carrier and the uplink carrier is transmitted as a system signal or an upper signal. A terminal supporting a CA can receive downlink data through a plurality of serving cells and transmit uplink data.

In the Rel-10, when it is difficult for a base station to transmit a Physical Downlink Control Channel (PDCCH) in a specific serving cell to a specific UE, a PDCCH is transmitted in another serving cell and the corresponding PDCCH is allocated to a Physical Downlink Shared Channel (PDSCH) A Carrier Indicator Field (CIF) can be set as a field for indicating that a Physical Uplink Shared Channel (PUSCH) is indicated. The CIF may be set to a terminal supporting CA. The CIF is determined to be able to indicate another serving cell by adding 3 bits to the PDCCH information in a specific serving cell. CIF is included only when performing cross carrier scheduling, and when the CIF is not included, cross carrier scheduling . When the CIF is included in the DL assignment, the CIF indicates a serving cell to which a PDSCH scheduled to be scheduled by the DL assignment is to be transmitted, and the CIF is included in uplink resource allocation information (UL grant) , The CIF is defined to point to the serving cell to which the PUSCH scheduled to be transmitted by the UL grant is to be transmitted.

As described above, Carrier Aggregation (CA), which is a bandwidth extension technique, is defined in the LTE-10, and a plurality of serving cells can be set to the UE. The UE periodically or non-periodically transmits channel information on the plurality of serving cells to the base station for data scheduling of the base station. The base station schedules data for each carrier and transmits the data, and the terminal transmits A / N feedback on the data transmitted for each carrier. The LTE Rel-10 is designed to transmit up to 21 bits of A / N feedback. When the A / N feedback and channel information transmission overlap in one subframe, the A / N feedback is transmitted and the channel information is discarded . LTE Rel-11 is designed to transmit A / N feedback of up to 22 bits and channel information of one cell to PUCCH format 3 in transmission resources of PUCCH format 3 by multiplexing channel information of one cell together with A / N feedback Respectively.

In LTE-13, a maximum of 32 serving cell configuration scenarios are assumed. The concept of extending the number of serving cells up to 32 using unlicensed band, which is a license-exempt band as well as license band, is completed. Also, considering the limited number of license bands, such as LTE frequencies, we have completed providing LTE services in unlicensed bands such as the 5GHz band, which we call Licensed Assisted Access (LAA). In LAA, we applied carrier-aggregation technology in LTE to support operation of P cell for licensed LTE cell and S cell for LAA cell that is license-exempted. Therefore, the feedback generated in the LAA cell, which is an S cell as in LTE, should be transmitted only in the P cell, and the downlink subframe and the uplink subframe can be freely applied to the LAA cell. Unless otherwise stated herein, LTE refers to all of the evolutionary technologies of LTE, such as LTE-A and LAA.

On the other hand, New Radio Access Technology (NR), a fifth generation wireless cellular communication system (hereinafter referred to as 5G in the present specification), which is a communication system after LTE, can freely reflect various requirements of users and service providers Services that satisfy various requirements can be supported.

Therefore, 5G is an example of an enhanced mobile broadband (eMBB) (hereinafter referred to as eMBB), massive machine type communication (hereinafter referred to as mMTC) A variety of 5G services such as Ultra Low Reliability and Low Latency Communications (hereinafter referred to as " URLLC ") will be referred to as a terminal maximum transmission rate of 20Gbps, a terminal maximum rate of 500km / , A terminal connection density of 1,000,000 terminals / km ^2, and the like, to satisfy the requirements selected for each of the 5G services.

For example, in order to provide eMBB at 5G, it is required to provide a maximum terminal transmission rate of 20Gbps in the downlink and a maximum terminal transmission rate of 10Gbps in the uplink from the viewpoint of one base station. At the same time, it is necessary to increase the average transmission speed that the terminal actually senses. In order to meet such requirements, improvement of transmission / reception technology including a further improved multiple-input multiple output transmission technique is required.

At the same time, mMTC is being considered to support application services such as the Internet of Thing (IoT) in 5G. In order to efficiently provide Internet of things, mMTC needs to support the connection of large terminals in a cell, enhancement of terminal coverage, improved battery time, and cost reduction of terminals. The Internet must be capable of supporting a large number of terminals (for example, 1,000,000 terminals / km ² ) in a cell by providing communication functions by being attached to various sensors and various devices. In addition, mMTC is required to have a wider coverage than eMBB because it is likely to be located in a shadow area such as an area where a terminal can not cover a cell or a building. The mMTC is likely to be configured as a low-cost terminal and requires a very long battery life time because it is difficult to frequently replace the battery of the terminal.

Finally, in the case of URLLC, cellular-based wireless communication used for a specific purpose is a service used for remote control, industrial automation, unmanned aerial vehicle, remote health control, emergency notification of robots or machinery , Ultra-low latency, and ultra-high reliability. For example, URLLC has a requirement to satisfy a maximum delay time of less than 0.5 ms and at the same time to provide a packet error rate of 10 ^-5 or less. Therefore, a transmission time interval (TTI) that is smaller than a 5G service such as an eMBB is required for URLLC, and a design requirement for allocating a wide resource in the frequency band is required.

The services considered in the above-mentioned fifth generation wireless cellular communication system should be provided as one framework. That is, for efficient resource management and control, it is preferable that each service is integrated into one system and controlled and transmitted rather than operated independently.

2B is a diagram showing an example in which services considered in 5G are multiplexed and transmitted to one system.

In FIG. 2B, the frequency-time resource 2b-01 used by 5G may be composed of a frequency axis 2b-02 and a time axis 2b-03. In FIG. 2B, 5G illustrates that eMBB (2b-05), mMTC (2b-06), and URLLC (2b-07) are operated by a 5G base station in one framework. In addition, as an additional service to be considered in 5G, an enhanced Mobile Broadcast / Multicast Service (eMBMS, 2b-08) for providing a broadcasting service on a cellular basis may be considered. Services considered in 5G such as eMBB (2b-05), mMTC (2b-06), URLLC (2b-07) and eMBMS (2b-08) (TDM) or Frequency Division Multiplexing (FDM), and spatial division multiplexing may also be considered. In the case of eMBB 2b-05, it is preferable to occupy and transmit the maximum frequency bandwidth at a specific arbitrary time in order to provide the above-mentioned increased data transmission rate. Therefore, it is preferable that the eMBB (2b-05) service is transmitted by TDM within the other service and system transmission bandwidth (2b-01). However, according to the needs of other services, .

In the case of mMTC (2b-06), unlike other services, an increased transmission interval is required in order to secure wide coverage, and coverage can be ensured by repetitively transmitting the same packet within the transmission interval. At the same time, in order to reduce the complexity of the terminal and the terminal price, the transmission bandwidth that the terminal can receive is limited. Considering these requirements, it is desirable that mMTC (2b-06) be transmitted in FDM with other services within 5G transmission system bandwidth (2b-01).

It is preferable that the URLLC (2b-07) has a short Transmit Time Interval (TTI) when compared with other services in order to satisfy the second delay requirement required by the service. At the same time, since it is necessary to have a low coding rate in order to satisfy the second reliability requirement, it is preferable to have a wide bandwidth on the frequency side. Considering the requirements of such URLLC (2b-07), it is desirable that URLLC (2b-07) is TDM with other services within the 5G transmission system bandwidth (2b-01).

Each of the services described above may have different transmission / reception techniques and transmission / reception parameters to satisfy the requirements of the respective services. For example, each service can have a different numerology depending on each service requirement. Numerology refers to a method of calculating a Cyclic Prefix (CP) length, a subcarrier interval, and a subcarrier spacing in a communication system based on Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) spacing, OFDM symbol length, transmission interval length (TTI), and the like. As an example having a different numerology between the above services, the eMBMS 2b-08 may have a longer CP length than other services. The eMBMS (2b-08) transmits the broadcast-based upper traffic, so that the same data can be transmitted from all the cells. At this time, if a signal received from a plurality of cells arrives within a CP length, the UE can receive and decode all of these signals, thereby obtaining a single frequency network (SFN) gain, Therefore, a terminal located at a cell boundary is also advantageous in that broadcasting information can be received without restriction of coverage. However, if the CP length is relatively long for supporting eMBMS in 5G, the CP overhead will cause waste, and at the same time, a longer OFDM symbol length is required compared to other services. A narrow subcarrier interval is required.

Also, as an example in which different Numerologies are used between services in 5G, in the case of URLLC, a shorter OFDM symbol length may be required as a smaller TTI is required compared to other services, and at the same time a wider subcarrier interval may be required.

In this paper, we describe the necessity of various services in order to satisfy various requirements in 5G, and describe the requirements for services that are considered as typical ones.

5G operates from several GHz to several tens of GHz, frequency division duplex (FDD) rather than time division duplex (TDD) is preferred over several GHz frequency bands, and FDD TDD is considered suitable. However, unlike FDD, which provides continuous uplink and downlink transmission resources by providing separate frequencies for uplink and downlink transmission, TDD must support both uplink and downlink transmission in one frequency and provide uplink or downlink resources only over time. Assuming that URLLC upstream transmission or downstream transmission is required in TDD, it is difficult to satisfy the second delay requirement required by URLLC due to delay until the uplink or downlink resource appears. Therefore, in order to satisfy the delay requirement of the URLLC in the case of TDD, there is a need for a method for dynamically changing the subframe upward or downward according to whether the data of the URLLC is upward or downward.

On the other hand, in the future, if 5G phase 2 or beyond 5G services and technologies are multiplexed on the 5G operating frequency, 5G phase 2 or beyond 5G technologies and services will be provided so that there is no backward compatibility problem in operation of the previous 5G technologies There are requirements to be made. These requirements are referred to as forward compatibility in the future, and technologies for satisfying compatibility in the future should be considered when designing the initial 5G. The lack of consideration of future compatibility in the initial LTE standardization phase can create constraints in providing new services within the LTE framework. For example, in the case of eMTC (Enhanced Machine Type Communication) applied in LTE release-13, in order to reduce the terminal cost by reducing the complexity of the terminal, the system transmission bandwidth provided by the serving cell Regardless, it is possible to communicate only at frequencies corresponding to 1.4MHz. Therefore, the UE supporting the eMTC can not receive the physical downlink control channel (PDCCH) transmitted in the entire bandwidth of the system transmission bandwidth. Therefore, in the time interval during which the PDCCH is transmitted, Constraints that can not be received occurred. Therefore, a 5G communication system must be designed so that the services under consideration after the 5G communication system operate with efficient coexistence with the 5G communication system. For future compatibility in the 5G communication system, it is necessary to freely allocate and transmit resource resources so that services to be considered in future can be freely transmitted in the time-frequency resource region supported by the 5G communication system. Accordingly, there is a need for a method for freely allocating time-frequency resources so as to support future compatibility in a 5G communication system.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, in the drawings, the same components are denoted by the same reference symbols as possible. Further, the detailed description of well-known functions and constructions that may obscure the gist of the present invention will be omitted.

The embodiments of the present invention will be described in detail with reference to LTE and 5G systems. However, the present invention is also applicable to other communication systems having a similar technical background and channel form. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

The following will describe a 5G communication system in which 5G cells operate in a stand-alone 5G communication system or in a non-stand alone mode combined with dual connectivity or carrier aggregation with other stand-alone 5G cells.

2C and 2D are views showing a second embodiment of a communication system to which the present invention is applied and a second embodiment of the present invention. The measures proposed by the present invention are applicable to both the system of FIG. 2C and the system of FIG. 2D.

Referring to FIG. 2C, a top view of FIG. 2C illustrates a case where a 5G cell 2c-02 operates in a stand-alone manner within one base station 2c-01 in the network. The terminal 2c-04 is a 5G capable terminal having a 5G transmission / reception module. The terminal 2c-04 obtains synchronization through the synchronization signal transmitted from the 5G stand-alone cell 2c-01, and attempts to perform random access to the 5G base station 2c-01 after receiving the system information. The terminal 2c-04 transmits and receives data through the 5G cell 2c-02 after the RRC connection with the 5G base station 2c-01 is completed. In this case, there is no restriction on the duplex method of the 5G cell (2c-02). In the system of FIG. 2C, the 5G cell may have a plurality of serving cells.

Next, the lower diagram of FIG. 2 shows that a 5G stand-alone base station 2c-11 and a 5G non-stand alone base station 2c-12 for increasing data transmission amount are installed. The terminal 2c-14 is a 5G capable terminal having a 5G transmission / reception module for performing 5G communication in a plurality of base stations. The terminal 2c-14 acquires synchronization through the synchronization signal transmitted from the 5G stand-alone base station 2c-11, and receives random access to the 5G stand-alone base station 2c-11 after receiving the system information Try it. The terminal 2c-14 additionally sets up a 5G non-stand alone cell 2c-15 after the RRC connection with the 5G stand-alone base station 2c-11 is completed and the 5G stand-alone base station 2c- 11) or 5G non-stand alone base station 2c-12. In this case, there is no restriction on the duplex method of the 5G stand-alone base station (2c-11) or the 5G non-stand alone base station (2c-12) It is assumed that the base station 2c-12 is connected to an ideal backhaul network or a non-ideal backhaul network. Therefore, fast base station X2 communication (2c-13) is possible with an ideal backhaul network (2c-13). In the system shown in the lower diagram of FIG. 2C, the 5G cell may include a plurality of serving cells.

2d, the upper diagram of FIG. 2d shows a case where LTE cells 2d-02 and 5G cells 2d-03 coexist in one base station 2d-01 in the network . The terminal 2d-04 may be an LTE capable terminal having an LTE transmission / reception module, a 5G capable terminal having a 5G transmission / reception module, or a terminal having an LTE transmission / reception module / 5G transmission / reception module at the same time. The terminal 2d-04 acquires synchronization through the synchronization signal transmitted from the LTE cell 2d-02 or the 5G cell 2d-03, (2d-02) or the 5G cell (2d-03). In this case, there is no restriction on the duplex scheme of the LTE cell (2d-02) or the 5G cell (2d-03). The uplink control transmission is transmitted through the LTE cell 2d-02 when the LTE cell is a P cell and through the 5G cell 2d-03 when the 5G cell is a P cell. In the system shown in the upper diagram of FIG. 2D, the LTE cell and the 5G cell may have a plurality of serving cells, and may support a total of 32 serving cells. It is assumed that the base station 2d-01 has both an LTE transmission / reception module (system) and a 5G transmission / reception module (system) in the network. The base station 2d-01 controls the LTE system and the 5G system in real time It is possible to operate. For example, if the LTE system and the 5G system are operated at different times by dividing resources in time, it is possible to dynamically select the allocation of time resources of the LTE system and the 5G system. The terminal 2d-04 transmits a resource (a time resource or a frequency resource or an antenna resource or a space resource) divided and operated by the LTE cell and the 5G cell from the LTE cell 2d-02 or the 5G cell 2d- By receiving the signal indicating the allocation, it is possible to know through which resources the data reception from the LTE cell 2d-02 and the 5G cell 2d-03 are respectively performed.

The lower diagram of FIG. 2d shows an LTE macro base station 2d-11 for wide coverage in the network and a 5G small base station 2d-12 for increasing data transmission capacity. The terminal 2d-14 may be an LTE capable terminal having an LTE transmission / reception module, a 5G capable terminal having a 5G transmission / reception module, or a terminal having an LTE transmission / reception module / 5G transmission / reception module at the same time. The terminal 2d-14 acquires synchronization through the synchronization signal transmitted from the LTE base station 2d-11 or the 5G base station 2d-12 and transmits the synchronization information to the LTE base station 2d- And transmits / receives data through the base station 2d-12. In this case, there is no restriction on the duplex mode of the LTE macro base station 2d-11 or the 5G small base station 2d-12. The uplink control transmission is performed through the LTE cell 2d-11 when the LTE cell is a P-cell and the 5G cell 2d-12 when the 5G cell is a P-cell. At this time, it is assumed that the LTE base station 2d-11 and the 5G base station 2d-12 have an ideal backhaul network or a non-ideal backhaul network. Therefore, even if the uplink transmission is transmitted only to the LTE base station 2d-11, it is possible to perform the fast X2 communication (2d-13) with the ideal backhaul network 2d-13, It is possible for the 5G base station 2d-12 to receive the relevant control information from the LTE base station 2d-11 in real time. In the system shown in the lower diagram of 2d, the LTE cell and the 5G cell may have a plurality of serving cells and may support a total of 32 serving cells. The base station 2d-11 or 2d-12 can manage the LTE system and the 5G system in real time. For example, when the base station 2d-11 divides resources on time and operates the LTE system and the 5G system at different times, it dynamically selects the allocation of time resources of the LTE system and the 5G system and transmits the signal to another base station 2d-12. The terminal 2d-14 transmits the resource (time resource, frequency resource, antenna resource, or spatial resource, etc.) divided and operated by the LTE cell and the 5G cell from the LTE base station 2d-11 or the 5G base station 2d- By receiving the signal indicating the allocation, it is possible to know through which resource the data transmission / reception from the LTE cell 2d-11 and the 5G cell 2d-12 takes place.

On the other hand, when the LTE base station 2d-11 and the 5G base station 2d-12 have a non-ideal backhaul network 2d-13, fast inter-base-station X2 communication 2d-13 is impossible. Therefore, the base station 2d-11 or 2d-12 can operate the LTE system and the 5G system semi-statically. For example, when the base station 2d-11 divides the resources in time and operates the LTE system and the 5G system at different times, it selects the time resource allocation of the LTE system and the 5G system, and transmits the signal to the other base station base station 2d-12), it is possible to distinguish resources between the LTE system and the 5G system. The terminal 2d-14 transmits the resource (time resource, frequency resource, antenna resource, or spatial resource, etc.) divided and operated by the LTE cell and the 5G cell from the LTE base station 2d-11 or the 5G base station 2d- By receiving the signal indicating the allocation, it is possible to know through which resource the data transmission / reception from the LTE cell 2d-11 and the 5G cell 2d-12 takes place.

Next, FIG. 2E is a diagram showing a situation to be solved by the present invention. When a time-frequency resource is freely allocated to support future compatibility in the 5G communication system through the upper and lower diagrams of FIG. 2E, a problem will be described when the base station implements the time-frequency resource so that the terminal does not know it .

In the upper diagram of FIG. 2E, the frequency-time resource 2e-01 used by 5G may be composed of frequency axis 2e-02 and time axis 2e-03. In the upper diagram of FIG. 2E, 5G illustrates that the MMCR (2e-06) and the Forward Compatibility Resource (FCR, 2e-08) are operated by the 5G base station in one framework. In the above, the FCR (2e-08) may be referred to as another name such as a compatibility guarantee resource or a compatibility guarantee resource. FCRs can also be referred to by other names, such as blank resources, reserved resources, and so on. For future compatibility and LTE-5G coexistence and other purposes (eg, when the URLLC is multiplexed, the eMBB terminal does not need to know the multiplexing of the URLLCs, thus setting the URLLC resource in the FCR) Which is a resource for securing in advance. In the present invention, all resources utilized for the above purpose are referred to as FCR.

As described previously, in the case of mMTC (2e-08), an increased transmission interval is required to secure wide coverage unlike other services, and coverage can be ensured by repetitively transmitting the same packet within the transmission interval. Therefore, when the FCR (2e-08) is set in a state where the UE does not know by the base station implementation, resources for FCR (2e-08) and mMTC (2e-08) collide with each other, The transmission can not be received. Therefore, it is necessary to define a signaling indicating the area of the FCR (2e-08) so that the terminal can perform an appropriate operation even in the case of a resource collision with another 5G service as described above. The proper operation of the UE includes a rate matching or a puncturing operation in the transmission resources of the 5G service that conflict with the FCR area. Rate matching is an operation of mapping data and transmitting and receiving mapped data considering only the remaining 5G transmission resources except for the transmission resources of the 5G service that conflict with the FCR region. Puncturing is performed in the transmission resources of the 5G service, which collide with the FCR region, The mobile station performs data demodulation considering only the reception values in the transmission resources of the 5G service that do not collide with the FCR area. (Alternatively, the reception value in the transmission resource of the 5G service colliding with the FCR area is processed as 0). The base station can transmit a signal indicating the rate matching or puncturing operation through an upper or a physical signal. The terminal receives the above signal and performs a rate matching or puncturing operation on the 5G service in the resource region that has collided with the FCR can do. Alternatively, the UE can perform a rate matching or puncturing operation according to predetermined 5G transmission signals. That is, when the FCR collides with the reference signal, the reference signal in the collided region can perform the puncturing operation. If the FCR and the 5G downlink control channel transmission region collide, the 5G downlink control channel transmission in the collided region is rate matching .

Next, the frequency-time resource 2e-11 used by the 5G in the lower diagram of FIG. 2e may be composed of the frequency axis 2e-12 and the time axis 2e-13. In the lower diagram of FIG. 2E, 5G illustrates that a channel reference RS (2e-14) and FCR (2e-18) for channel information measurement are operated by a 5G base station in one framework.

The channel reference signal 2e-14 may be transmitted over a wide frequency band by the base station. The frequency band of the channel reference signal 2e-14 can be previously set as an upper signal. The terminal measures the channel reference signal 2e-14 in the set frequency band, generates channel information according to the channel reference signal 2e-14, do. Therefore, when the FCR 2e-18 is set in a state where the UE does not know by the base station implementation, resources for the FCR 2e-18 and the channel reference signal 2e-18 collide with each other, In the state where the resource of the signal 2e-18 is not known to be occupied by the FCR, the channel reference signal 2e-18 is measured to generate erroneous channel information and feed back the channel information to the base station. Therefore, it is necessary to define a signaling indicating the area of the FCR (2e-18) so that the terminal can perform an appropriate operation even in the case of a resource collision with the reference signal for another 5G service as described above.

Next, signaling for indicating the area of the FCR proposed in the present invention will be described.

The signaling signaling the FCR region may include at least a frequency or time domain. In particular, the downlink frequency domain, the time domain, the uplink frequency domain, and the time domain can be separately defined. Also, the time domain of the FCR may be composed of one slot or at least one slot, which is a time unit used for transmitting and receiving data by the eMBB terminal. The slot may be composed of 7 or 14 OFDM symbols if the slot includes 60 kHz or less, or may be set to an upper signal among 7 or 14 slots. The slot may be composed of 14 OFDM symbols when it exceeds 60 KHz. Also, the time domain of the FCR may consist of mini-slots or subslot units or at least one mini-slot or subslot, which is a time unit used for transmitting and receiving data by a URLLC terminal. The mini-slot or subslot may be composed of fewer than seven OFDM symbols. Also, the time domain of the FCR can be composed of a smaller number of OFDM symbols than slots or mini-slots. Also, the uplink or downlink frequency region of the FCR may be a physical resource block (PRB) unit consisting of 12 subcarriers or a subband unit composed of at least one PRB. Also, the frequency domain of the FCR may be composed of a smaller number of subcarrier units than the PRB. The signaling signaling the FCR region may mean that the actual FCR is used by the base station and there may be signaling signaling the FCR region and signaling indicating whether the actual FCR is used by the base station. Signaling indicating the FCR region and signaling indicating whether the actual FCR is used by the base station may be a signal for a particular terminal, a signal for a particular service (eMBB or URLLC or mMTC, for example) Signal, or a 5G release-specific signal. The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

Signals indicating the FCR region or signaling signals indicating whether an actual FCR is used by the base station may be transmitted from the base station to the mobile station as an upper signal or a physical signal and the terminal may acquire the signals and transmit the FCR region and the FCR It is possible to determine whether the region is actually used by the base station and to perform a predefined proper procedure when the FCR region collides with the 5G service region or the 5G signal.

When a plurality of FCRs are set up from a base station, the setting information can be transmitted to the terminal through an upper signal, and the base station can transmit a plurality of FCRs to the FCR To the terminal through the physical signal. The terminal receives setting information (a bit signal indicative of a frequency or a time domain, period information in which the FCR is repeated, and the like) for the plurality of FCRs as an upper signal, and transmits a physical signal (common downlink control channel or dedicated downlink control channel) And receives information of the FCR activated among the plurality of FCRs. If it is determined that the remaining FCR is inactivated through the reception of the activated FCR information and the activated FCR conflicts with the data reception or RS reception of the terminal, the method operates according to the method proposed by the present invention. If the inactive FCR conflicts with the data reception or RS reception of the terminal, the terminal ignores the deactivated FCR and normally transmits data (assuming that the FCR resource is not set) even if the inactive FCR resource overlaps with the data resource or the RS resource And RS.

Alternatively, bit information including whether each FCR is activated or deactivated in an upper signal for setting a plurality of FCRs may be included. The base station transmits FCR setting information and activation / deactivation information to the terminal through the upper signal , The terminal operates according to the method proposed by the present invention when the activated FCR receives the upper signal and collides with the data reception or RS reception of the terminal. If the inactive FCR conflicts with the data reception or RS reception of the terminal, the terminal ignores the deactivated FCR and normally transmits data (assuming that the FCR resource is not set) even if the inactive FCR resource overlaps with the data resource or the RS resource And RS.

Or whether the FCR including at least one time domain (subframe or slot or mini-slot or subslot) and frequency domain (subband or PRB or subcarrier) is set / unset or activated / deactivated Bit information to a physical signal (common downlink control channel or dedicated downlink control channel) or an upper signal. The FCR may be selected from a time or a frequency resource in which the UE should receive the downlink control channel. The base station can transmit to the mobile station information indicating that a specific time, frequency, time / frequency combining interval is set / not set or activated / deactivated through the transmission of the physical signal or the upper signal. Or attempt to decode the downlink control channel only for the inactive FCR, and not to attempt to decode the downlink control channel for the set or activated FCR, thereby saving the transmission power of the terminal.

Or whether the FCR including at least one time domain (subframe or slot or mini-slot or subslot) and frequency domain (subband or PRB or subcarrier) is set / unset or activated / deactivated Bit information to a physical signal (common downlink control channel or dedicated downlink control channel) or an upper signal. The above FCR may be selected from time or frequency resources for which the UE should measure the downlink channel. The base station can transmit information indicating that a specific frequency interval is set or activated / deactivated to the mobile station through transmission of the physical signal or the upper signal. The terminal receives the FCR signal and determines that the time domain or the frequency domain included in the FCR that is not set or deactivated is valid for downlink channel measurement, and attempts to measure the downlink channel. The terminal receives the FCR signal and determines that the time domain or the frequency domain included in the set or activated FCR is not valid for the downlink channel measurement and saves the terminal power by not attempting the downlink channel measurement.

Next, referring to FIG. 2F, a description will be made of the 2-1 embodiment proposed in the present invention in the case of collision with the FCR area and the 5G service area.

FIG. 2F is a view showing the embodiment 2-1 of the present invention.

The frequency-time resource 2f-01 used by 5G in FIG. 2F may be composed of frequency axis 2f-02 and time axis 2f-03. In FIG. 2F, 5G illustrates that eMBBs (2f-04, 2f-05) and FCR (2f-08) are operated by a 5G base station in one framework. In this figure, FCR and resource (2f-05) of an eMBB collide with each other. However, the present invention can be applied not only to eMBB but also to resources of other 5G services such as mMTC, URLLC and eMBMS.

The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

The rate matching or the puncturing operation can be performed according to the predetermined order for each 5G transmission signal. Signaling of whether or not the FCR area and the FCR are actually used is transmitted to the terminal. When the FCR (2f-08) collides with an area where eMBB data should be transmitted / received by data scheduling of the eMBB (2f-05) It is determined that the transmission of the FCR 2f-08 is prioritized and the eMBB data is mapped in the resource overlapping with the area of the FCR (2f-08) among the areas where the eMBB data is transmitted and received by the data scheduling of the eMBB (2f- I never do that. That is, if the UE overlaps the FCR region with respect to the reference signal for eMBB data and data demodulation, if the rate matching is preliminarily determined, the UE removes the resource element in the overlapping region, determines that eMBB data is transmitted and received, and transmits and receives data. The UE collides with the area of the FCR (2f-08) among the areas where the eMBB data is transmitted / received by the data scheduling of the eMBB (2f-05) according to the signal instructing to perform the rate matching or puncturing operation, And perform rate matching or puncturing operation of the reference signal for data demodulation.

Next, the operations of the base station and the terminal will be described in the case of a collision with the FCR area and the 5G service area through FIG. 2G.

FIG. 2G is a diagram illustrating a procedure of a base station and a terminal according to a second embodiment of the present invention.

First, the base station procedure according to the embodiment 2-1 of the present invention will be described.

In step 2g-10, the base station transmits FCR-related information to the UE. The FCR related information includes signaling indicating the area of the FCR as described in the present invention, and is transmitted according to the method described in the present invention. The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

In step 2g-11, the BS transmits data scheduling information for the 5G service to the MS. The data scheduling information includes all services considered for 5G as described in the present invention, and the data scheduling information includes frequency resources or time resources for data transmission of the 5G service. The data scheduling information may be transmitted by an upper signal or a physical signal.

In step 2g-12, the base station transmits and receives data except for the FCR area according to the data scheduling information for the 5G service. In case of downlink, the base station maps the data to the resources excluding the FCR region among the scheduled data resources and transmits the data. In case of uplink, the base station receives data from resources other than the FCR region among the scheduled data resources.

Next, the terminal procedure according to the embodiment 2-1 of the present invention will be described.

In step 2g-20, the terminal receives the FCR-related information from the base station. The FCR related information includes signaling indicating the area of the FCR as described in the present invention, and is transmitted according to the method described in the present invention. The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

In step 2g-21, the UE receives data scheduling information for the 5G service from the BS. The data scheduling information includes all services considered for 5G as described in the present invention, and the data scheduling information includes frequency resources or time resources for data transmission of the 5G service. The data scheduling information may be transmitted by an upper signal or a physical signal.

In step 2g-22, the terminal transmits and receives data except for the FCR area according to data scheduling information for the 5G service to the base station. In the case of downlink, the UE receives data from resources other than the FCR region among the scheduled data resources. In case of the uplink, the base station maps data from the resources excluding the FCR region among the scheduled data resources.

Next, referring to FIG. 2H, a description will be made of the second embodiment, which is proposed in the present invention, in the case where signals for the FCR area and the 5G service collide with each other.

2H is a view showing a second embodiment of the present invention.

In Fig. 2H, the frequency-time resource 2h-01 used by 5G may be composed of a frequency axis 2h-02 and a time axis 2h-03. In FIG. 2h, 5G illustrates that eMBB (2h-04, 2h-05) and FCR (2h-08) are operated by a 5G base station in one framework. When data of eMBB is transmitted, channel reference signals (2h-06, 2h-07) for referring to channel information are transmitted for eMBB data scheduling. In this figure, the channel reference signals for the FCR and eMBB services collide with each other. However, not only eMBB but also other 5G services such as mMTC, URLLC, eMBMS or other reference signals (for example, data demodulation reference signals, Signal, etc.) in the case of a collision with the transmission.

The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

The rate matching or the puncturing operation can be performed according to the predetermined order for each 5G transmission signal. When the FCR (2h-08) collides with the channel reference signal (2h-07) for channel information measurement, the terminal transmits FCR (2h-08) (2h-07) among the resources 2h-06 and 2h-07 to which the channel reference signal is transmitted conflicts with the region of the FCR (2h-08) . That is, if puncturing is preliminarily determined when the FCR region overlaps with the reference signal transmission region for channel information measurement, the terminal measures only the remaining channel reference signals except for the resource element in the overlapping region, And transmits the channel information to the base station. The terminal collides with the area of the FCR (2h-08) among the resources (2h-06, 2h-07) to which the channel reference signal is transmitted according to the signal instructing to perform the rate matching or puncturing operation, ), The channel reference signal can be rate matched or punctured.

2I is a diagram illustrating a procedure of a base station and a terminal according to a second embodiment of the present invention.

First, the base station procedure according to the embodiment 2-2 of the present invention will be described.

In step 2i-10, the base station transmits FCR-related information to the UE. The FCR related information includes signaling indicating the area of the FCR as described in the present invention, and is transmitted according to the method described in the present invention.

The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

In step 2i-11, the BS transmits a reference signal to the UE except for the FCR region. The reference signal includes all of the reference signals for services considered for 5G as described in the present invention. The setting information of the reference signal can be transmitted by an upper signal or a physical signal.

Next, the terminal procedure according to the embodiment 2-2 of the present invention will be described.

In step 2i-20, the terminal receives FCR-related information from the base station. The FCR related information includes signaling indicating the area of the FCR as described in the present invention, and is transmitted according to the method described in the present invention.

In step 2i-21, the terminal receives the reference signal except for the FCR area from the base station. The reference signal includes all of the reference signals for services considered for 5G as described in the present invention. The setting information of the reference signal can be transmitted by an upper signal or a physical signal. After receiving the reference signal in step 2i-21, the terminal performs an operation according to the reference signal based on the received reference signal. For example, in the case of a channel reference signal, the terminal generates channel information based on the received channel reference signal, and feeds back the generated channel information to the base station.

Next, a description will be made of the second to third embodiments of the present invention when there is a 5G phase 2 or beyond 5G terminals capable of transmitting and receiving data in the FCR when there is a collision of signals for the FCR area and the 5G service.

Signaling of whether or not the FCR area and the FCR are actually used is transmitted to the UE and the 5G phase 2 or beyond 5G UE can receive data from the FCR when the FCR collides with the channel reference signal for channel information measurement , Data and reference signals that may be transmitted in the FCR. In this case, the 5G phase 2 or beyond 5G terminal receives both the reference signal transmitted from the FCR and the reference signal transmitted from the FCR region, generates one channel information from the signals, and transmits the channel information to the base station . Since channel information is generated from more channel reference signals and transmitted to the base station, the base station can more accurately schedule data from the channel information.

2J is a diagram illustrating a procedure of a base station and a terminal according to the second and third embodiments of the present invention.

First, the base station procedure according to the second to third embodiments of the present invention will be described.

In step 2j-10, the BS transmits FCR-related information to the MS. The FCR related information includes signaling indicating the area of the FCR as described in the present invention, and is transmitted according to the method described in the present invention.

The signaling signal indicating the FCR region may include a signal for instructing the terminal to perform a rate matching or puncturing operation in the case of a collision with a 5G service area or a 5G service area in which the terminal collided with the FCR.

In step 2j-11, the BS transmits a reference signal not only to the FCR area but also to the UE outside the FCR area. The reference signal includes all of the reference signals for services considered for 5G as described in the present invention. The setting information of the reference signal can be transmitted by an upper signal or a physical signal.

Next, a terminal procedure according to the second and third embodiments of the present invention will be described.

In step 2j-20, the terminal receives FCR-related information from the base station. The FCR related information includes signaling indicating the area of the FCR as described in the present invention, and is transmitted according to the method described in the present invention.

In step 2j-21, the UE receives both the reference signal in the FCR area and the reference signal in the FCR area from the base station. The reference signal includes all of the reference signals for services considered for 5G as described in the present invention. The setting information of the reference signal can be transmitted by an upper signal or a physical signal. After receiving the reference signal in step 2j-21, the terminal performs an operation according to the reference signal based on the received reference signal. For example, in the case of a channel reference signal, the terminal generates channel information based on the received channel reference signal, and feeds back the generated channel information to the base station.

Next, FIG. 2K illustrates a base station apparatus according to the present invention.

The controller 2k-01 allocates 5G resources according to the base station, terminal procedure according to the present invention of FIGS. 2g, 2i, and 2j, and the operation method of data / reference signal collision of FCR and 5G service according to FIG. The scheduler 2k-03 schedules the 5G data in the 5G resource and controls the 5G resource allocation information transmission apparatus 2k-03 to transmit the 5G data to the terminal through the 5G resource allocation information transmission apparatus 2k- And transmits and receives 5G data to and from the 5G terminal through the data transmission / reception device (2k-07).

Next, FIG. 21 shows a terminal device according to the present invention.

The 5G resource allocation information receiving apparatus 2l-05 according to the base station and the terminal procedure according to the present invention of Figs. 2g, 2i, and 2j and the operation method of the data / reference signal collision of the FCR and 5G service according to the present invention, The controller 2l-01 receives 5G resource allocation (FCR and 5G service area and 5G signal setting) from the base station via the 5G data transceiver 2l-06 for the 5G data scheduled in the allocated 5G resource, To / from the 5G base station.

≪ Third Embodiment >

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting a time-contiguous reference signal.

In a wireless communication system, a base station must transmit a reference signal for estimating a channel. The terminal can demodulate the received signal using channel estimation using the reference signal. Also, the terminal can use the reference signal to grasp the channel state and feed it back to the base station. Generally, when transmitting a reference signal, the transmission interval between the frequency and the time of the reference signal is determined in consideration of the maximum delay spread and the maximum Doppler spread of the channel. As the transmission interval between the frequency and time of the reference signal is narrowed, the channel estimation performance is improved and the demodulation performance of the signal can be improved. However, this results in increasing the overhead of the reference signal and limiting the data transmission rate.

Conventionally, 4G LTE systems operating in the 2GHz frequency band use reference signals such as CRS (cell-specific reference signal) and DMRS (demodulation reference signal) in the downlink. Assuming that the interval of the reference signal in the frequency domain is represented by a subcarrier interval m of an Orthogonal Frequency Division Multiplexing (OFDM) signal and the interval of the reference signal is represented by a symbol interval n of the OFDM signal in time, , And the transmission interval between the frequency-time of the reference signal corresponding to antenna ports 1 and 2 is (m, n) = (3, 4). Also, in case of DMRS assuming normal CP, the transmission interval between frequency and time of reference signal is (m, n) = (5,7).

Unlike the LTE system, the 5G wireless communication system considers a system operating in a higher frequency band than the 6GHz frequency band. Since the channel characteristics depend on the frequency band, it is necessary to design the reference signal in consideration of this in the 5G system. In addition, low latency support and high mobility support are considered important in 5G wireless communication. In addition, in the 5G system, it is important to minimize the interference and overhead that the reference signal is generated, and there is a need to minimize the transmission of the reference signal at all times. Accordingly, the present invention provides a method for efficiently performing channel estimation by introducing a time-contiguous reference signal in order to solve such a problem.

For example, 3GPP's High Speed Packet Access (HSPA), LTE (Long Term Evolution or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced To a broadband wireless communication system that provides high-speed, high-quality packet data services such as the LTE-A, 3GPP2 high rate packet data (HRPD), UMB (Ultra Mobile Broadband), and IEEE 802.16e communication standards. . In addition, a 5G or NR (new radio) communication standard is being produced with the fifth generation wireless communication system.

In the LTE / LTE-A system, a typical example of the broadband wireless communication system is an Orthogonal Frequency Division Multiplexing (OFDM) scheme in a downlink (DL) Carrier Frequency Division Multiple Access (CDMA) scheme. The uplink refers to a radio link through which a UE (User Equipment) or an MS (Mobile Station) transmits data or control signals to a base station (eNode B or base station (BS) The term " wireless link " In the above multiple access scheme, the data or control information of each user is classified and operated so that the time and frequency resources for transmitting data or control information for each user do not overlap each other, that is, orthogonality is established. do.

FIG. 3A is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource region in which the data or control channel is transmitted in the downlink in the LTE / LTE-A system.

In Fig. 3A, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol, and N _symb (102) OFDM symbols constitute one slot 106, and two slots form one subframe 105. The length of the slot is 0.5 ms and the length of the subframe is 1.0 ms. The radio frame 114 is a time domain including 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the total system transmission bandwidth is composed of a total of N _BW (104) subcarriers.

In a time-frequency domain, a basic unit of a resource can be represented by an OFDM symbol index and a subcarrier index as a resource element (RE) 112. A resource block (RB or Physical Resource Block) 108 is defined as N _symb (102) consecutive OFDM symbols in the time domain and N _RB (110) consecutive subcarriers in the frequency domain. Thus, one RB 108 is comprised of N _symb x N _RB REs 112. In general, the minimum transmission unit of data is the RB unit. In the LTE system, N _symb = 7, N _RB = 12, and N _BW and N _RB are generally proportional to the bandwidth of the system transmission band. The data rate increases in proportion to the number of RBs scheduled to the UE. The LTE system defines and operates six transmission bandwidths. In the case of an FDD system in which the downlink and the uplink are classified by frequency, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Table 2 below shows the correspondence between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system with a 10 MHz channel bandwidth has a transmission bandwidth of 50 RBs.

[Table 2]

FIG. 3B is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource region in which data or control channels are transmitted in an uplink in an LTE / LTE-A system according to the related art.

Referring to FIG. 3B, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an SC-FDMA symbol 202, and N _symb ^UL SC-FDMA symbols form one slot 206. Then, two slots form one subframe 205. The minimum transmission unit in the frequency domain is a subcarrier, and the total system transmission bandwidth 204 is composed of a total of N _BW subcarriers. N _BW has a value proportional to the system transmission band.

The basic unit of resources in the time-frequency domain is a resource element (RE) 212, which can be defined as an SC-FDMA symbol index and a subcarrier index. A resource block pair (RB pair) 208 is defined as N _symb ^UL consecutive SC-FDMA symbols in the time domain and N _sc ^RB consecutive subcarriers in the frequency domain. Therefore, one RB consists of N _symb ^UL x N _sc ^RB REs. In general, the minimum transmission unit of data or control information is RB unit. In case of PUCCH, it is mapped to a frequency region corresponding to 1 RB and transmitted for 1 sub-frame.

3C shows a radio resource of 1 RB which is a minimum unit that can be downlink-scheduled in the LTE / LTE-A system. A plurality of different types of signals may be transmitted to the radio resource shown in FIG.

One. CRS (Cell Specific RS): A reference signal periodically transmitted for all UEs belonging to one cell, and can be commonly used by a plurality of UEs.

2. Demodulation Reference Signal (DMRS): A reference signal transmitted for a specific terminal and is transmitted only when data is transmitted to the terminal. The DMRS can be composed of a total of 8 DMRS ports. In LTE / LTE-A, port 7 to port 14 correspond to the DMRS port, and ports maintain orthogonality so that they do not interfere with each other using CDM or FDM.

3. PDSCH (Physical Downlink Shared Channel): A data channel transmitted in the downlink, which is used for the base station to transmit traffic to the UE and is transmitted using the RE in which the reference signal is not transmitted in the data region of FIG. 2

4. CSI-RS (Channel Status Information Reference Signal): Used to measure the channel status of a reference signal transmitted for UEs belonging to one cell. A plurality of CSI-RSs can be transmitted to one cell.

5. Other control channels (PHICH, PCFICH, PDCCH): The terminal transmits ACK / NACK for providing control information necessary for receiving PDSCH or HARQ for uplink data transmission

Since the channel estimation performance directly affects the demodulation performance as a reference signal used for demodulating a signal received through channel estimation in the case of CRS and DMRS in the signal, a transmission interval between the frequency and the time of the reference signal considering the channel estimation performance is maintained have. Specifically, if the intervals of the reference signals on the frequency are represented by the subcarrier spacing m of the OFDM signal and the intervals of the reference signals are represented by the symbol spacing n of the OFDM signal in time, (M, n) = (3, 4). Also, in case of DMRS assuming normal CP, the transmission interval between frequency and time of reference signal is (m, n) = (5,7).

Unlike the LTE system, the 5G wireless communication system considers a system operating in a higher frequency band than the 6GHz frequency band. Since the channel characteristics depend on the frequency band, it is necessary to design the reference signal in consideration of this in the 5G system. In addition, low latency support and high mobility support are considered important in 5G wireless communication. In addition, in the 5G system, it is important to minimize the interference and overhead that the reference signal is generated, and there is a need to minimize the transmission of the reference signal at all times. Accordingly, the present invention provides a method for efficiently performing channel estimation by introducing a time-contiguous reference signal in order to solve such a problem.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Embodiments of the present invention will be described below as an example of an LTE or LTE-A system, but the embodiments of the present invention can be applied to other communication systems having a similar technical background or channel form. For example, 5G mobile communication technology developed after LTE-A (5G, new radio, NR) could be included. More specifically, the basic structure of the time-frequency domain in which signals are transmitted in downlink and uplink may be different from FIG. 3A and FIG. 3B. And the types of the signals transmitted through the uplink and the downlink may be different. Therefore, the embodiments of the present invention can be applied to other communication systems by a person skilled in the art without departing from the scope of the present invention.

In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification. Hereinafter, the base station may be at least one of an eNode B, a Node B, a base station (BS), a wireless access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing communication functions. In the present invention, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a mobile station, and an uplink (UL) is a wireless transmission path of a signal transmitted from a mobile station to a base station.

The time contiguous reference signal (TCRS) described below is used as an abbreviation TCRS for convenience of explanation. However, the terminology for TCRS can be expressed in other terms depending on the intent of the user and the intended use of the reference signal. For example, terms such as a channel tracking reference signal (CTRS), a phase noise reference signal (PNRS), a phase noise compensation reference signal (PCRS), or a phase reference signal (PRS). However, the abbreviation TCRS as described above is merely a specific example of the present invention and is not intended to limit the scope of the present invention in order to facilitate understanding of the present invention. That is, it is apparent to those skilled in the art that the present invention can be applied to a reference signal based on the technical idea of the present invention.

In the embodiment 3-1 of the present invention to be described below, the structure and position in the time-frequency domain of the TCRS will be described. In the embodiment 3-2 of the present invention, a method of setting the TCRS by the base station will be described. The operation of the terminal according to the set TCRS will be described in the embodiment 3-3 of the present invention.

[Example 3-1]

The 3-1 embodiment describes the structure of the reference signal TCRS of the present invention and the position in the time-frequency domain. FIG. 3D is a diagram showing the structure of TCRS. As shown in FIG. 3D, the TCRS has a property of being transmitted on the time axis in the time-frequency domain of the transmitted resource. Specifically, they may be transmitted continuously on the time axis, or they may be located very close to each other on the time axis. On the frequency axis, the signal may be transmitted only in a specific frequency domain as shown in FIG. 3D, or may be transmitted on a frequency axis. 3E is a diagram showing an example of using a more specific TCRS based on the LTE / LTE-A system. FIG. 3E is a view showing positions in the time-frequency domain of the DMRS and the TCRS proposed in the present invention. As mentioned above, since 5G wireless communication considerably supports low latency, the reference signal DMRS may be located in front of the subframe, as shown in FIG. 3E, in order to quickly perform channel estimation. However, the channel estimation performance may not be guaranteed in the low SNR region (-10 to 0 dB) only by the DMRS located in the front of the subframe. In addition, there is a disadvantage in that it can not treasure the channel change over time in a high speed situation. In this case, if the TCRS is used as shown in FIG. 3E, the problem can be solved through channel trekking for the symbol in which the TCRS is located. In a 5G system operating at high frequencies, TCRS may also be used to compensate for phase noise. In FIG. 3E of FIG. 3E, the TCRS occupies one subcarrier per RB in the frequency domain and is repeatedly transmitted every 4 RBs. However, the present invention is not limited thereto. For example, as shown in FIG. 3D, the TCRS may be repeatedly transmitted every X RB (X 1) on the basis of FIG. 3E, and the TCRS may occupy all subcarriers of one RB, have. Also, in FIG. 3E of the 3-1 embodiment, although the TCRS is located in the OFDM symbol after the DMRS in the time domain, the location where the TCRS is transmitted in time is not limited thereto. For example, TCRS may also be transmitted in an OFDM symbol prior to the DMRS based on FIG. 3E, and when the 5G system has a basic structure of a time-frequency domain different from the LTE / LTE-A system, the TCRS is transmitted in time The location may vary. Assuming that a self-contained subframe is used in the 5G system and the last X (X > = 1) OFDM symbols of the subframe are used in the uplink, TCRS may not be transmitted in this area. If TCRS overlaps with another reference signal, TCRS can be set prioritized. Although the structure and time-frequency location of the TCRS are described based on the downlink in the embodiment 3-1, if OFDMA is used in the uplink in the 5G system, the structure of the TCRS described in the 3-1 embodiment and And the position on the time-frequency may be set equal to the downlink and uplink.

[Example 3-2]

The embodiment 3-2 provides a method for the base station to set the reference signal TCRS of the present invention. First, TCRS has a common method for all UEs belonging to one cell (which may be a sector or a TRP) and UE-specific setting for one UE. The common setting of TCRS is a method of transmitting UE-specific precoding to a reference signal similar to CRS in LTE system. The UE-specific setting of TCRS is similar to that of DMRS in LTE system. Lt; RTI ID = 0.0 > UE-specific < / RTI > Since there are advantages and disadvantages in the above two methods in the operation of the TCRS, both of the methods are proposed in the present invention.

First, if TCRS is set as common, all UEs belonging to one cell (which may be a sector or TRP) acquire additional information by using TCRS as well as channel trekking and a reference signal that is commonly transmitted similar to LTE CRS Can be utilized. Additional information that can be obtained by setting the TCRS to be common may vary depending on the location in the time-frequency domain of the TCRS. For example, assuming that the TCRS occupies one subcarrier per RB in the frequency domain and is repeatedly transmitted every 4 RBs, assuming that the TCRS is transmitted every subframe in the full band, , RRM measurement, Doppler spread, delay spread measurement). It can also be used to measure frequency offset using the characteristics of TCRS transmitted continuously on time axis. However, when the TCRS is commonly set in the present invention, the difference between the CRS and the CRS of the existing LTE is that the overhead of the reference signal can be lowered compared to the CRS. Referring to FIG. 3C, in case of CRS of LTE, TCRS of the present invention can be set not to be transmitted every RB in the frequency domain as compared with that transmitted every RB in every full band, and RRC setting or dynamic signaling You can use a method that allows you to set the TCRS not to be sent for a specific time. The method of turning off the proposed TCRS setting will be described in more detail in the following examples. However, if TCRS is set to be common, there is a disadvantage that the performance may be deteriorated when channel-trekking is performed on UE-specific beamformed transmitted signals.

In contrast, UE-specific setting of TCRS enables more accurate channel trekking for UE-specific beamformed signals compared with a common TCRS setting method. However, when the TCRS is UE-specific, when an orthogonal transmission layer is allocated to each UE considering multi-user (MU) transmission, the TCRS resolution is degraded on the time axis. A method of allocating an orthogonal transport layer to each terminal is shown in FIG. FIG. 3F-1 shows that the time resolution of the TCRS is lowered when a method of allocating four transmission layers to each terminal in the TDM scheme is used. FIG. 3F-2 shows that the time resolution of the TCRS is lowered when a method of allocating four transmission layers to each MS in the CDM scheme is used. Therefore, as a method for securing the disadvantage that the resolution of the TCRS is reduced when the orthogonal transmission layer is allocated to each UE, it is possible to allocate the TCRS in a time-sequential manner as shown in FIG. 3f-3, assuming the same phase drift for all transmission layers May be used. In other words, the last method is to use only one antenna port for TCRS.

The advantages and disadvantages of TCRS are compared in common or UE-specific settings. In the following, a method of setting the TCRS to be multiple in the present invention and a function of turning off the TCRS setting will be described. First, setting the TCRS to multiple is a way to minimize interference between cells (which may be sector or TRP). Different TCRS can be set to the UE by setting TCRS to multiple. An example of a method for setting four different TCRS is shown in FIG. 3G. However, the method of setting TCRS to multiple in the present invention is not limited thereto. More specifically, in the present invention, multiple TCRS can be set in the following manner. Table 3 below shows how TCRS is set to a higher layer like RRC. Here, TCRS-ConfigNZPId represents the set value of TCRS, and maxTCRS-NZP (maxTCRS-NZP≥0) multiple TCRS can be set. If TCRS-ConfigNZPId = 0, it means that TCRS is not transmitted. At this time, the terminal can assume that data is transmitted in the TCRS region. If TCRS-ConfigNZPId ≠ 0, the value of TCRS-ConfigNZPId indicates the position of TCRS transmission, and the UE can assume that the reference signal is transmitted at the corresponding TCRS position.

[Table 3]

It is possible to set TCRS to be common or UE-specific through the method of setting TCRS proposed in the present invention through the above-mentioned 3-2 embodiment. In addition to the method of setting TCRS to multiple, the function of turning off the TCRS setting minimizes the interference caused by the reference signal and minimizes the transmission of the reference signal always on.

[Example 3-3]

The operation of the UE based on the structure and the setting of the TCRS, which is the reference signal of the present invention, will be described in Example 3-3. In the third to eighth embodiments, the TCRS proposed in the present invention can be set to be common or UE-specific. The operation of each terminal is described below when the setting of TCRS is set to be common or UE-specific.

First, when TCRS is UE-specific, TCRS can be transmitted only in the resource allocated band, and the location where TCRS is transmitted can be determined by the allocated band. For LTE, the PRB bundling size set for the DMRS is determined by the system bandwidth. The present invention proposes that the bundling size to which TCRS is applied can be determined by a multiple of the PRB bundling size set for the DMRS. And the TCRS may be allocated in one or more of the bundling sizes in which the TCRS is transmitted. When the TCRS is UE-specific, the starting location of the TCRS transmission among the RBs allocated to the UE can be determined based on the initial position of the allocated RB. The operation of the UE using the TCRS when the TCRS is UE-specific is described in more detail with reference to FIG. 3H-1. In FIG. 3h-1, it is assumed that seven RBs have been allocated to UE-A, a PRB bundling size set for DMRS is 4, and a bundling size to which TCRS is applied is set to 4 in the same manner. It is assumed that the start position of the TCRS is repeatedly transmitted every 4 RBs based on the first position of the allocated RB. Then, the UE reflects the bundling size to which the TCRS is applied, and performs channel estimation using the TCRS allocated thereto. More specifically, the UE performs channel estimation using the TCRS A in the upper 4 RBs of the 7 RBs allocated to the UE-A in FIG. 3h-1, and the lower 3 RBs allocated to the UE- To perform channel estimation.

Next, when the TCRS is set to be common, the TCRS can be transmitted in the full band, and the transmission position of the TCRS can be determined by the allocated band. For LTE, the PRB bundling size set for the DMRS is determined by the system bandwidth. The present invention proposes that the bundling size to which TCRS is applied can be determined by a multiple of the PRB bundling size set for the DMRS. And the TCRS may be allocated in one or more of the bundling sizes in which the TCRS is transmitted. The operation in which the UE uses the TCRS when the TCRS is set to be common will be described in more detail with reference to FIG. 3H-2. It is assumed that the PRB bundling size set for the DMRS in FIG. 3h-2 is 4, and the bundling size to which the TCRS is applied is similarly set to 4. And is transmitted repeatedly every 4 RBs in the entire TCRS band. Then, the UE reflects the bundling size to which the TCRS is applied, and performs channel estimation using the TCRS allocated thereto. More specifically, the UE can perform channel estimation using TCRS A for the three RBs allocated to the UE-A in FIG. 3H-2.

In the third to third embodiments, the bundling size to which the TCRS is applied can be determined to be a multiple of the PRB bundling size set for the DMRS. And TCRS proposed that TCRS can be assigned to one or more within bundling size to be transmitted. If the bundling size to which the TCRS is applied is set larger than the PRB bundling size set for the DMRS, the UE can advantageously perform channel estimation using more TCRS, while a scheduling proposal may occur. The terminal can perform the terminal operation using the TCRS on the assumption of the method proposed in the third embodiment.

In order to perform the above-described embodiments of the present invention, the transmitter, the receiver and the processor of the terminal and the base station are shown in Figs. 3i and 3j, respectively. In order to perform an operation of transmitting and receiving a time-contiguous reference signal from the 3-1 to 3-3 embodiments, a transmitting and receiving method of a base station and a terminal is shown. To perform this operation, The receiving unit, the processing unit, and the transmitting unit of the terminal must operate according to the embodiment, respectively.

3I is a block diagram illustrating an internal structure of a UE according to an embodiment of the present invention. As shown in FIG. 3I, the terminal of the present invention may include a terminal receiving unit 1800, a terminal transmitting unit 1804, and a terminal processing unit 1802. The terminal receiving unit 1800 and the terminal may be collectively referred to as a transmitting unit 1804 in the embodiment of the present invention. The transmitting and receiving unit can transmit and receive signals to and from the base station. The signal may include control information and data. To this end, the transmitting and receiving unit may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, an RF receiver for low-noise amplifying the received signal and down-converting the frequency. The transceiving unit may receive a signal through a wireless channel, output the signal to the terminal processing unit 1802, and transmit the signal output from the terminal processing unit 1802 through a wireless channel. The terminal processor 1802 may control a series of processes so that the terminal can operate according to the embodiment of the present invention described above. For example, the terminal receiving unit 1800 receives the time-sequential reference signal from the base station, and the terminal processing unit 1802 can control the interpretation of the application method of the time-series reference signal. Also, the terminal transmission unit 1804 can also transmit the time-sequential reference signal.

3J is a block diagram illustrating an internal structure of a base station according to an embodiment of the present invention. 3J, the base station of the present invention may include a base station receiving unit 1901, a base station transmitting unit 1905, and a base station processing unit 1903. [ The base station receiving unit 1901 and the base station transmitting unit 1905 may be collectively referred to as a transmitting / receiving unit in the embodiment of the present invention. The transmitting and receiving unit can transmit and receive signals to and from the terminal. The signal may include control information and data. To this end, the transmitting and receiving unit may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, an RF receiver for low-noise amplifying the received signal and down-converting the frequency. The transceiving unit may receive a signal through a wireless channel, output the signal to the base station processing unit 1903, and transmit the signal output from the terminal processing unit 1903 through a wireless channel. The base station processor 1903 can control a series of processes so that the base station can operate according to the above-described embodiment of the present invention. For example, the base station processor 1903 may determine a transmission position on a time-frequency of a time-sequential reference signal and generate configuration information of the time-sequential reference signal to be transmitted to the terminal. Subsequently, the base station transmitter 1905 transmits the time-sequential reference signal and the configuration information to the terminal, and the base station receiver 1901 receives the time-sequential reference signal in the configuration.

Also, according to an embodiment of the present invention, the base station processor 1903 can control to generate a Radio Resource Control (RRC) including configuration information of the time-sequential reference signal. In this case, the RRC may indicate the configuration information of the time-sequential reference signal.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of the present invention in order to facilitate the understanding of the present invention and are not intended to limit the scope of the present invention. That is, it will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible. Further, each of the above embodiments can be combined with each other as needed. For example, the base station and the terminal can be operated by combining the embodiments 3-1, 3-2, and 3-3 of the present invention with each other. Although the above embodiments are presented on the basis of the FDD LTE system, other systems based on the technical idea of the above embodiment may be implemented in other systems such as a TDD LTE system, a 5G or NR system.

Claims (1)

A method for processing a control signal in a wireless communication system,
Receiving a first control signal transmitted from a base station;
Processing the received first control signal; And
And transmitting the second control signal generated based on the process to the base station.

Images